Signaling and packet relay method and system including general packet radio service (&#34;GPRS&#34;)

ABSTRACT

A method and system for roaming mobile communications between networks is described. One embodiment includes a plurality of messages from a home network subscriber device that is device is roaming outside the home network. A communications link is established with a destination network, including modifying at least one of the messages such that the message appears to the destination network to originate from a partner network of the destination network. Both voice and data are transmitted via the communications link.

RELATED APPLICATION

[0001] This application claims priority from U.S. Provisional PatentApplication No. 60/447,533, filed Feb. 14, 2003, which is incorporatedby reference herein in its entirety.

TECHNICAL FIELD

[0002] The disclosed embodiments relate to wireless communicationssystems. In particular, disclosed embodiments relate to roaming wirelesscommunications, in which a subscriber of a network provider communicatesoutside the provider's home network.

[0003] Acronyms

[0004] International Mobile Subscriber Identity (of HPMN) (IMSI);

[0005] Mobile Subscriber ISDN Number (phone number) (MSISDN);

[0006] Single IMSI Multiple MSISDN Service (SIMM);

[0007] Subscriber Identity Module (SIM);

[0008] Home Public Mobile Network who intends to provide MSISDN Service(HPMN);

[0009] Foreign Public Mobile Network who intends to partner with HPMNfor Multiple MSISDN Service (FPMN);

[0010] Mobile Switching Center (MSC);

[0011] Signaling Gateway (SG);

[0012] Gateway MSC (GMSC);

[0013] GMSC in HPMN (GMSC-H);

[0014] GMSC in FPMN (GMSC-F);

[0015] GMSC in VPMN (GMSC-V);

[0016] MSISDN of the Multiple MSISDN Service allocated by HPMN in HPMNnumbering plan (MSISDN-H);

[0017] MSISDN of the Multiple MSISDN Service subscriber in the FPMN(Co-operating VPMN) numbering plan (MSISDN-F);

[0018] Signaling System 7 (SS7);

[0019] Visited Mobile Switching Center (VMSC);

[0020] Serving VMSC in HPMN (VMSC-H);

[0021] Serving VMSC in FPMN (VMSC-F);

[0022] Serving VMSC in VPMN (VPMN is not HPMN/FPMN) (VMSC-V);

[0023] Associated Public Mobile Network for SMS Inter-working (APMN);

[0024] Call Detail Record (CDR);

[0025] Call Forwarding in Busy (CFB);

[0026] Call Forwarding on Not Reachable (CFNR);

[0027] Call Forwarding on No Reply (CFNRy);

[0028] Call Forwarding Unconditional (CFU);

[0029] Circuit Switch Data (CSD);

[0030] Digital Distribution Frame (DDF);

[0031] Forwarded-To-Number typically used in Call Forwarding (FTN);

[0032] General Packet Radio Service (GPRS);

[0033] Gateway GPRS Service Node (GGSN);

[0034] GPRS Roaming Exchange (GRX);

[0035] Serving GPRS Service Node (SGSN);

[0036] Global Title (SS7 parlance) (GT);

[0037] Home Location Register (HLR);

[0038] Intelligent Network (IN);

[0039] Intelligent Network Application Part (INAP);

[0040] Inter Operator SMS within HPMN (IOSMS);

[0041] International Roaming Expert Group (IREG);

[0042] ISDN User Part message from SS7 stack (ISUP);

[0043] Interactive Voice Response (IVR);

[0044] Late Call Forwarding (LCF);

[0045] Message Application Part (from GSM 09.02 GSM Standards) (MAP);

[0046] Mobile Global Title (derived from IMSI) (MGT);

[0047] Mobile Station Roaming Number (MSRN);

[0048] Originally Called Number (OCN) (same as ODN);

[0049] Originally Dialed Number (ODN) (same as OCN);

[0050] Outreach Messaging (Enhanced version of legacy SMS Welcome) (OM);

[0051] Optimized Routing (OR);

[0052] Packet Data Protocol (PDP);

[0053] Provide Roaming Number MAP message (PRN);

[0054] Service Control Point (SCP);

[0055] Signal Control Connection Part (SCCP);

[0056] Send Routing Information MAP message (SRI);

[0057] Short Message Service (SMS);

[0058] Short Message Service Center (SMSC);

[0059] SMSC in HPMN (SMSC-H);

[0060] SMSC in APMN (where APMN is not HPMN or FPMN) (SMSC-A);

[0061] SMSC in FPMN (SMSC-F);

[0062] Transfer Accounting Procedure (TAP);

[0063] Transfer Accounting Data Interchange Group (TADIG);

[0064] Transaction Capability Part (TCAP);

[0065] Translation Type (SS7 parlance) (TT);

[0066] Virtual Home Environment (VHE);

[0067] Visited Location Register (VLR);

[0068] Serving VLR in HPMN (VLR-H);

[0069] Serving VLR in FPMN (VLR-F);

[0070] Serving VLR in VPMN (VPMN is not HPMN/FPMN) (VLR-V);

[0071] Visited Public Mobile Network (other than HPMN or FPMN) (VPMN);

[0072] Wireless Fidelity (WiFi);

[0073] Basic Call State Model (BCSM);

[0074] Customized Applications for Mobile network Enhanced Logic(CAMEL);

[0075] Camel related message from SCF to SSF (Connect, Continue);

[0076] Detection Point (DP);

[0077] Deflected To Number (DTN);

[0078] Dialled Services CAMEL Subscription Information (D-CSI);

[0079] Event Detection Point (EDP);

[0080] Gateway MLC (GMLC);

[0081] GPRS Service Switching Function (gprsSSF);

[0082] GPRS CAMEL Subscription Information (GPRS-CSI);

[0083] GSM Service Control Function (gsmSCF);

[0084] GSM Specialised Resource Function (gsmSRF);

[0085] GSM Service Switching Function (gsmSSF);

[0086] Home PLMN (HPLMN);

[0087] InitialDP (IDP);

[0088] Information Element (IE);

[0089] Information Flow (IF);

[0090] Intelligent Peripheral (IP);

[0091] Interrogating PLMN (IPLMN);

[0092] Location Services (LCS);

[0093] Localised Service Area (LSA);

[0094] Mobility Management event Notification CAMEL SubscriptionInformation (M-CSI);

[0095] Mobile Forwarding (MF);

[0096] Mobile Location Center (MLC);

[0097] Mobile Originating (MO);

[0098] Mobile Terminating in GMSC (MT);

[0099] Network CAMEL Service Information (N-CSI);

[0100] North American (NA);

[0101] Network Node Interface (NNI);

[0102] Originating Basic Call State Model (O-BCSM);

[0103] Originating CAMEL Subscription Information (O-CSI);

[0104] Operator Determined Barring (ODB);

[0105] Operator Specific Service (OSS);

[0106] Packet Data Protocol (PDP);

[0107] Point In Call (PIC);

[0108] Public Land Mobile Network (PLMN);

[0109] Serving GPRS Support Node (SGSN);

[0110] Service Logic Program Instance (SLPI);

[0111] Service Management Function (SMF);

[0112] Serving MLC (SMLC);

[0113] Short Message Service CAMEL Subscription Information (SMS-CSI);

[0114] Supplementary Service Notification CAMEL Subscription Information(SS-CSI);

[0115] Terminating Basic Call State Model (T-BCSM);

[0116] Terminating CAMEL Subscription Information (in the GMSC) (T-CSI);

[0117] Trigger Detection Point (TDP);

[0118] Transfer Protocol Data Unit (TPDU);

[0119] Translation Information Flag (TIF-CSI);

[0120] USSD CAMEL Subscription Information (U-CSI);

[0121] USSD General CAMEL Service Information (UG-CSI);

[0122] User Network Interface (UNI);

[0123] Visited PLMN (VPLMN);

[0124] Mobile Terminating in VMSC (VT);

[0125] VMSC Terminating CAMEL Subscription Information (VT-CSI);

[0126] Charging data collection interface between a CDR transmittingunit (e.g. an SGSN or a GGSN) and a CDR receiving functionality (a CGF)(Ga);

[0127] Interface between an SGSN and a BSS (Gb);

[0128] Interface between a GGSN and an HLR (Gc);

[0129] Interface between an SMS-GMSC and an SGSN, and between anSMS-IWMSC and an SGSN (Gd);

[0130] Interface between an SGSN and an EIR (Gf);

[0131] Reference point between GPRS and a packet data network (Gi);

[0132] Interface between two GSNs within the same PLMN (Gn);

[0133] Interface between two GSNs in different PLMNs (Gp) (the Gpinterface allows support of GPRS network services across areas served bythe co-operating GPRS PLMNs);

[0134] Interface between an SGSN and an HLR (Gr);

[0135] Interface between an SGSN and an MSC/VLR (Gs);

[0136] Interface between the RNS and the core network (Iu) (alsoconsidered as a reference point);

[0137] Kilobits per second (kbit/s);

[0138] Megabits per second (Mbit/s) (1 Mbit/s=1 million bits persecond);

[0139] Reference point between a non-ISDN compatible TE and MT(typically this reference point supports a standard serial interface)(R);

[0140] The service area for which the location of an MS is reported(Reporting Area);

[0141] The location accuracy level needed for service managementpurposes in the 3G-SGSN, e.g. a routeing area or a cell (the 3G-SGSN canrequest the SRNC to report: i) the MS's current service area; ii) whenthe MS moves into a given service area; or iii) when the MS moves out ofa given service area) (Service Area);

[0142] Interface between the mobile station (MS) and the A/Gb modenetwork. The Um interface is the MS to network interface for providingGPRS services over the radio to the MS (Um);

[0143] Interface between the mobile station (MS) and the Iu modenetwork. The Uu interface is the Iu mode network interface for providingGPRS services over the radio to the MS (Uu).

BACKGROUND

[0144] Traditionally, there are certain requirements for establishing aroaming relationship between two wireless communication networkoperators. These requirements include, network connectivity (forexample, SS7 and/or Internet Protocol (IP)), a procedure for exchangingbilling information, and a commercial roaming agreement (such as AA12-14or AA31). These requirements must be met before International RoamingExpert Group (IREG) and Transferred Account Data Interchange Group(“TADIG”) tests can be applied. With reference to FIG. 1, a traditionalroaming scenario 100 is illustrated. An operator A 102 has anInternational Roaming Agreement 104 with an operator B 103. The operatorA 102 has a fixed network 106A, a GSM system 108A, including a VisitedLocation Register (VLR) and a Home Location Register (HLR), an EDPcenter 110A, a billing system 112A, and finance software and hardware114A. The operator B 103 has a fixed network 106B, a GSM system 108B,including a Visited Location Register (VLR) and a Home Location Register(HLR), an EDP center 10B, a billing system 112B, and finance softwareand hardware 114B. A subscriber 118 is a subscriber of operator B, butis roaming on the network of operator A. A subscriber 116 is asubscriber of operator A, but is roaming on the network of operator B.

[0145] As shown, the operators A and B communicate according to IREG andTADIG tests.

[0146] In voice roaming, network connectivity is established byInternational Switch Center (ISC) carriers or by direct connection.However, connectivity is generally the easiest part of establishingroaming. The more time time-consuming and/or difficult part isestablishing a commercial agreement between the two operators beforeIREG and TADIG testing can proceed. Often, it is not a high priority fornetwork operators to deal with smaller operators to set up roamingrelationships. In addition, often it is not a high priority for networkoperators to set up roaming relationships with other operators incountries where the network operator already has at least one existingroaming relationship.

[0147] One approach to facilitating roaming is to piggyback onpreviously established roaming relationships, or partnerships. Thepartner operator is often called the sponsoring operator, and thepiggybacking operator is often called the sponsored operator.

[0148] All current solutions that allow a sponsored operator topiggyback on the roaming relationships of a sponsoring operator onlywork for voice and Short Message Service (SMS) roaming. In thesesolutions, Message Application Part (MAP) signaling between thesponsored operator and the targeting roaming partner are relayed througha signal gateway that “fools” the targeting roaming partner into thinkit is dealing with the sponsoring network. For outbound roamers of thesponsored operator, a sponsoring operator IMSI is used in a dual IMSISIM when roaming so the IMSI-Sponsoring is being replaced by thecorresponding IMSI-Sponsored when the MAP signal is relayed through thesignal gateway. The MAP signaling relay can also control MT-calls toinbound roamers from a target roaming partner to be routed through thesponsoring operator if desired.

[0149] While these prior solutions can be extended to deal with CAMELand GPRS MAP signaling, no existing solutions allow a sponsored operatorto piggyback on a sponsoring operator's GPRS roaming relationships. GPRSroaming involves both signaling and data sessions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0150] Embodiments of the invention are described with the aid of thedrawings, which are not intended to be limiting. In the drawings,similar reference numbers identify similar elements or acts.

[0151]FIG. 1 is a block diagram illustrating a traditional roamingscenario.

[0152]FIG. 2 is a block diagram showing subsystems of one embodiment ofa signal processing component.

[0153]FIG. 3 is block diagram of an embodiment of a GPRS roamingscenario.

[0154]FIG. 4 is a block diagram showing an embodiment for an inboundroamer (for example, an orange UK inbound roamer).

[0155]FIG. 5 is a block diagram showing an embodiment for an outboundroamer.

[0156]FIG. 6 is a block diagram illustrating a private connection optionin which an SPRS node has a private SS7 connection.

[0157]FIG. 7 is a block diagram illustrating a configuration for aglobal title modification option and a Mobile Number Portability (MNP)option, which modifies the called address by prefixing it with a routingnumber.

[0158]FIG. 8 is a block diagram illustrating a configuration in whichthere is an SPRS node at each network.

[0159]FIG. 9 is an illustration of an architecture 900 that supportsCAMEL.

[0160]FIG. 10 is a block diagram of an embodiment that supports CAMEL.

[0161]FIG. 11 is a block diagram of an embodiment in which a UKsubscriber is roaming in SmarTone Macau using the SGSN of SmarToneMacau.

[0162]FIG. 12 is a block diagram of an embodiment in which a SmarToneMacau subscriber is roaming in Orange UK, using the SGSN of Orange UK.

[0163]FIG. 13 is a block diagram of an embodiment in which multiple SPRSnodes are connected to the SmarTone HK GMSCs in a cross-connected mode.

[0164]FIG. 14 is a block diagram of an embodiment in which multiple SPRSnodes are connected to the same SmarTone HK GMSC.

[0165]FIG. 15 is a block diagram of an example billing framework foroutbound roamers.

[0166]FIG. 16 is a block diagram of an example billing framework forinbound roamers.

DETAILED DESCRIPTION

[0167] Embodiments of an enhanced signal gateway, or Signaling PacketRelay System (SPRS), that accommodates General Packet Radio Service(GPRS) are described. In contrast to pure voice roaming solutions inwhich only signaling is relayed, the SPRS system also relays Packet DataProtocol (PDP) packets for GPRS. Unlike voice calls, data sessions alsocarry information about the IMSI, so the IMSI of a sponsoring operatormust be mapped to that of the sponsored operator. As an illustration, ifoperator A has a GPRS roaming relationship with operator B, and operatorB has GPRS capability described herein, then operator A will havevirtual GPRS roaming relationships with any operator C with whichoperator B has a roaming relationship. An advantage of the describedapproach is that it allows virtual roaming between two roaming GPRSoperators (who are not related by a roaming agreement) by piggybackingon a middleman operator who has roaming relationship with bothoperators. A data session is relayed thru a GPRS-enhanced signal gatewayto “fool” the targeting roaming partner's GPRS network into thinkingthat it is transferring data with the sponsoring operator's GPRSnetwork.

[0168] With reference to FIG. 2, a GPRS roaming scenario 200 accordingto one embodiment is illustrated. An operator A 202 has an InternationalRoaming Agreement 204 with an operator B 203. The operator A 202 has afixed network 206A, a GSM system 208A, including a Visited LocationRegister (VLR) and a Home Location Register (HLR), an EDP center 210A, abilling system 112A, and finance software and hardware 214A. Theoperator B 203 has a fixed network 206B, a GSM system 208B, including aVisited Location Register (VLR) and a Home Location Register (HLR), anEDP center 210B, a billing system 212B, and finance software andhardware 214B. A subscriber 218 is a subscriber of operator B, but isroaming on the network of operator A. A subscriber 216 is a subscriberof operator A, but is roaming on the network of operator B. The scenario200 further includes a GPRS Roaming Exchange (GRX) 222 that provides aGPRA connection between the appropriate hardware and software 220A ofoperator A and corresponding hardware and software 220B of operator B.

[0169] GPRS roaming involves both SS7 connectivity and IP connectivity.Accordingly, both voice and data roaming will be used to illustratevarious embodiments. For purposes of illustrating various embodiments,two network operators, SmarTone Macau and SmarTone HK will be used inexamples. SmarTone Macau is a relatively new GSM operator in Macau. Itcould take SmarTone Macau a long time to negotiate with otherinternational GSM operators for roaming agreements. To solve thisexample problem, an embodiment of a Signal and Packet Relay System(SPRS) is deployed SmarTone Macau or in SmarTone HK/Macau. Using thisSPRS node, SmarTone Macau can piggyback on the roaming relationships ofSmarTone HK to offer outbound roamers immediate roam services around theworld. Just as importantly, SmarTone Macau can offer service to inboundroamers to Macua from all over the world.

[0170] Desciptions of embodiments of the SPRS follow, including examplesof logistics, signal flows, and billing strategies. The embodimentssupport both inbound and outbound communications from a networksignaling perspective, although there may be additional logisticsinvolved with outbound roaming support (for example, with respect toSIMs and billing).

[0171] According to various embodiment, a broad strategy for SPRS withGPRS, using SmarTone Macau and SmarTone HK as example operators, is asfollows. When a SmarTone Macau subscriber roams in an example billingframework for outbound roamers from a United Kingdom (UK) network, orany other network except SmarTone HK, the UK network is made to thinkthat they are a SmarTone HK subscriber and not a SmarTone Macausubscriber.

[0172] When an Orange UK subscriber roams in SmarTone Macau, the UKnetwork must be made to think that it is roaming in SmarTone HK. TheSmarTone Macau network need not be made to think that the subscriber isfrom SmarTone HK.

[0173] When a SmarTone Macau subscriber roams in SmarTone HK, or inoperators who already have a roaming relationship with SmarTone Macau,they appear as a SmarTone Macau subscriber (which is a normal roamingscenario). Thus SmarTone HK or the roaming partners are treated as aspecial case, or an exception to the rule that a roaming SmarTone Macausubscriber appears as a SmarTone HK subscriber whenever they roamoutside SmarTone Macau.

[0174] In this broad strategy, all MAP messages from SmarTone Macau toUK are trapped, and transformed to look to the UK as if they are comingfrom SmarTone HK. Messages From the UK that seem to be addressed toSmarTone HK, but are actually for SmarTone Macau are identified andtransformed so that they get routed to the appropriate network (e.g.SmarTone Macau).

[0175] For data roaming, all GPRS session messages are trapped, and thesponsoring IMSI is replaced by the sponsored IMSI. This is accomplishedby acting as a proxy to relay GPRS packets over two tunnels. One tunnelis between UK and SPRS at the sponsoring operator and the other tunnelis between SPRS and the sponsored operator SmarTone Macau.

[0176] According to the broad strategy, one embodiment is a solution inwhich aSPRS node is introduced into a SmarTone HK/Macau network. In oneembodiment, this is an SS7/MAP node with full SCCP capability (e,g,Global Title Translation and Routing). All international roamingmessages with outbound roamers and inbound roamers from networks with noroaming relationship with SmarTone Macau (non-roaming partners) arerouted via the SPRS.

[0177] Signal Transfer Point (STP) tables in the SmarTone HK are used toroute all messages from non-roaming partners of SmarTone Macau to thenew signaling node. The STP tables in SmarTone Macau are configured toroute all messages from SmarTone Macau to the new signaling node. Thesignaling node modifies the messages as appropriate, and sends them outthrough a GMSC.

[0178] For data roaming, the SPRS node supports a Gp interface. The SPRSnode can establish PDP context with both UK and the SmarTone MacauGGSN/SGSN, and relay PDP packets between the two tunnels.

[0179]FIG. 3 is a block diagram illustrating an embodiment 300 for aninbound roamer 302 (for example, an orange UK inbound roamer). Theembodiment 300 includes an SGSN 304, and a VLR 306 for SmarTone Macau.SmarTone HK includes an SPRS signal gateway 310. Orange UK includes aGGSN 312 and an HLR 314. There are two PDP tunnels accomplished by a GRX308A between SmarTone Macau and SmarTone HK, and a GRX 308B betweenSmarTone HK and Orange UK. The VLR 306 and the SGSN 304 communicate withthe SPRS 310 via an SS7 connection 316A. The SPRS 310 furthercommunicates with the HLR 314 via an SS7 connection 316B.

[0180] The Orange UK subscriber 302 is roaming in SmarTone Macau. TheSmarTone Macau VLR 306 and SGSN 304 send a location update to the UKoperator. This message is directed to the SPRS signal gateway 310. Thismessage must be modified in SmarTone HK to make it look as if it wasbeing sent by a SmarTone HK VLR/SGSN 306/304. It is then sent to the UKHLR 314. The UK HLR 314 responds with an Insert Subscriber Data messageaddressed to the (fictitious) SmarTone HK VLRISGSN 306/304. Thesignaling node realizes that the message is actually meant for theSmarTone Macau VLR/SGSN 306/304, modifies the relevant fields, androutes it accordingly. For data roaming, when the UK subscriber accessesan APN, the PDP tunnel 308A is established between the SmarTone MacauSGSN 304 and the SPRS 310, and the PDP tunnel 308B is also establishedbetween the SPRS 310 and the UK GGSN 312. Packets are relayed across thetwo tunnels.

[0181]FIG. 4 is a block diagram illustrating an embodiment 400 for anoutbound roamer 402 (for example, a SmarTone Macau outbound roamer). Theembodiment 400 includes an GGSN 404, and an HLR 406 for SmarTone Macau.SmarTone HK includes an SPRS signal gateway 410. Orange UK includes anSGSN 412 and a VLR 414. There are two PDP tunnels accomplished by a GRX408A between SmarTone Macau and SmarTone HK, and a GRX 408B betweenSmarTone HK and Orange UK. The VLR 414 and the SGSN 412 communicate withthe SPRS 410 via an SS7 connection 416B. The SPRS 410 furthercommunicates with the HLR 406 via an SS7 connection 416A.

[0182] The SmarTone Macau subscriber 402 is roaming in Orange UK using adual IMSI SIM. Orange UK will see the SmarTone HK IMSI because it has aroaming relationship with SmarTone HK. The subscriber 402 must (manuallyor automatically) select the SmarTone HK IMSI profile in the SIM toregister with Orange UK. SmarTone HK relays the message through the SPRS410 to transform the message for sending on to the SmarTone Macaunetwork elements. The SmarTone Macau HLR 406 sees the SmarTone MacauIMSI as an IMSI provisioned in the HLR 406.

[0183] For data roaming, when the SmarTone Macau subscriber 402 accessesan APN, the PDP tunnel 408A is established between the SmarTone MacauGGSN 404 and the SPRS 410. The PDP tunnel 408B is established betweenthe SPRS 410 and the Orange UK SGSN 412. Packets are relayed across thetwo tunnels.

[0184] If the subscriber 402 roams in SmarTone HK or SmarTone Macau, oroperators that already have a roaming relationship with SmarTone Macau,using the SmarTone HK IMSI, the signaling relay rejects the registrationrequest.

[0185] It is possible that SmarTone Macau has a voice roamingrelationship with operator X but not a GPRS roaming relationship). Inthis case, whether an “update location request” is rejeced depends onwhether it is a VLR update location, or as SGSN update location request.In both cases, SmarTone HK will direct any update location with thespecific IMSI range to the SPRS 410. If it is a GPRS request, and ifthere is no GPRS roaming relationship, then it is processed normally,otherwise, it is rejected. If it is a VLR request, and if there is novoice roaming relationship, then it is processed normally, otherwise, itis rejected.

[0186] There are logistics associated with inbound roaming support.There are additional logistics associated with outbound roaming support.Some aspects of these logictics are described below.

[0187] Dual IMSI or Special Single IMSI SIM for Outbound Roamers

[0188] To enable SmarTone Macau subscribers to roam in foreign networksthat do not have a roaming relationships with SmarTone Macau, but have aroaming relationship with SmarTone HK, the subscribers are provided adual-IMSI SIM card. One IMSI is a SmarTone Macau IMSI, while the otheris a SmarTone HK IMSI. The SmarTone HK IMSI is related to the SmarToneMacau IMSI in the following manner:

[0189] SmarTone Macau IMSI: 455-00-12345 (provisioned in SmarTone MacauHLR)

[0190] SmarTone HK IMSI: 454-06-09-12345 (not provisioned in/recognizedby any HLR)

[0191] Here SmarTone HK allocates a special range of IMSIs indicated by“09” for the SmarTone Macau outbound roamers. “09” is just an example.SmarTone HK is free to use any prefixes for this purpose. It is possiblein other embodiments to use a table to map a special SmarTone HK IMSIwith a SmarTone Macau IMSI. This approach involves database access.

[0192] Orange UK (an example network) sees the SmarTone HK IMSI becauseit has a roaming relationship with SmarTone HK. SmarTone Macau HLR seesthe SmarTone Macau IMSI because that is the one provisioned in the HLR.

[0193] If the subscriber roams in SmarTone HK or operators that alreadyhave a roaming relationship with SmarTone Macau, or SmarTone Macau withthe SmarTone HK IMSI, the signaling relay node rejects the registrationrequest.

[0194] For outbound data roaming, SmarTone HK assigns some fictitiousSmarTone HK APNs that correspond to the real APNs of SmarTone Macau. Inthis way, when the SmarTone Macau outbound roamers are in the UKnetwork, the fictitious SmarTone HK APN is chosen in order to access thereal APN of SmarTone Macau.

[0195] For inbound data roaming, SmarTone Macau arranges with its GRXprovider or DNS server for any APN of an operator that does not have adata roaming relationship with SmarTone Macau to return the SPRS as thethe GGSN.

[0196] Under the profile of the SmarTone HK IMSI in the dual IMSI SIM,the SMSC address is a specially assigned SmarTone HK E164 numbercorresponding to a SmarTone Macau SMSC address. However APNs aregenerally not on the SIM; they can be created or transmitted over theair (OTA'd) to the handset.

[0197] All security related functions and parameters of SmarTone Macauremain as before. In particular, authentication is done using SmarToneMacau's HLR, regardless of the IMSI profile selected.

[0198] The SPRS also supports a special single IMSI SIM set up withoutany change to the SPRS node. The SIM only contains the speciallyallocated SmarTone HK-IMSI and its associated profile (e.g. a SmarToneHK SMSC address that corresponds to a SmarTone Macau SMSC). Thesubscriber thus obtains a new SIM. This approach simplifies the userinterface for subscribers and may be more cost-effective on the SIMside. However on the network side there are still two IMSIs, and theyare related in the same way as previously described. The signaling flowalso remains the same. The Single vs Dual IMSI SIM decision is typicallymade by the smaller network, e.g., SmarTone Macau in our examples. IfSmaiTone Macau uses the Single IMSI SIM approach, SmarTone Macau willconfigure its SCCP/GTT routing on the special SmarTone HK IMSI throughthe SPRS node even though the SmarTone Macau subscriber is in Macau. Inaddition, SmarTone Macau must modifies its billing process to recognizethat CDRs generated for a special range of SmarTone HK IMSIs areactually from its own subscribers.

[0199] Dual IMSI SIM or special Single IMSI SIM as described is not arequirement for supporting inbound roamers who register with theSmarTone Macau network. However, according to our examples, SmarToneMacau is a relatively smaller network that can expect more inbound,visiting roamers than outbound, subscriber roamers. The architecture andthe signaling node are the same in either case, and services to inboundand outbound roamers can be implemented incrementally or all at once.The only difference is that in one instance (for outbound roamers) adual IMSI or a special Single IMSI SIM is issued. All SIM relatedfunctions (e.g. manually or automatically select a profile, network IMSImapping, SMSC addresses) are worked out by SmarTone Macau and SmarToneHK.

[0200] Billing Issues

[0201] Whether for inbound roamers or outbound roamers, TAP files andinvoices are exchanged between the foreign network and SmarTone HK, forexample through a clearing house. All billing related issues are workedout by SmarTone HK and SmarTone Macau (as example operators).

[0202] SS7 Routing Options

[0203] The SPRS may be physically located in SmarTone Macau, or inSmarTone HK, or in both networks depending on the routing optionsadopted.

[0204] There are several routing options, and the choice might depend onthe various network environments. Some options are technically simplerbut logistically more challenging, and hence potentially more costly.Other options are technically more complex but logistically simpler.Various SS7 routing options are described below.

[0205] Translation Type

[0206] Translation type is one SS7 routing option. In this option, withreference to FIG. 5, SmarTone Macau and SmarTone HK each havetranslation type support. SmarTone Macau includes a GMSC 502A and anSPRS 506. SmarTone HK includes a GMSC 502B. An STP 504A and an STP 504Bare situated as shown. An existing ISC carrier, for example REACH, alsodedicates a translation type (e.g. 31) for this service. The SPRS nodeis physically located in SmarTone HK, which is responsible for assigninga SPC (Signal Point Code) to the SPRS node. SmarTone HK assigns a poolof SmarTone HK-GTs to the SPRS node. The size of the pool is the same asthe number of HLRs and SMSCs in SmarTone Macau.

[0207] The SmarTone Macau-GMSC is configured in its GTT in such a waythat all CdPA destined for international GTs (GTs that have no roamingrelationships with SmarTone Macau) are routed through the REACH STPwithout changing the routing indicator. That is, they are still routingon the GT. The GTT function introduces the specially agreed upontranslation type (e.g. 31). The REACH GTT is configured in such a waythat, for a SCCP message of the special translation type (e.g. 31), itroutes the SCCP message to the SmarTone HK GMSC. The SmarTone HK-GMSC isconfigured in its GTT in such a way that all GTs with the specialtranslation type (e.g. 31) re mapped to the SPRS SPC.

[0208] The SPRS node modifies the Calling GT, and possibly other MAPparameters (e.g., IMSI) to a specially assigned SmarTone HK GT thatcorresponds to the calling GT. The mapping can be statically defined atthe SPRS and dynamically created at the time of assignment. The formermay be more advisable, because if the dynamic mapping is corrupted inthe latter approach, reset and restoration procedures must be performed.

[0209] The SPRS node retains a routing indicator on the GT. Whenreceiving a message with the special translation type, the SPRS modifiesthe CgPA to its corresponding SmarTone HK GT and sends the message tothe SmarTone HK GMSC with translation type 0. When receiving a messageincluding the CdPA with the special SmarTone HK GT assigned for SmarToneMacau, the SPRS modifies the CdPA (e.g. SmarTone HK-MGT, SmarToneHK-GT-FOR-SmarTone Macau-HLR, SmarTone HK-GT-FOR-SmarTone Macau-SMSCetc) to its corresponding SmarTone Macau GT (e.g. SmarTone Macau-MGT,SmarTone Macau-HLR, SmarTone Macau-SMSC) and send the message to theSmarTone HK GMSC.

[0210] One advantage of this approach include the relative simplicity ofconnection set up. On the other hand, to use this approach, theoperators, e.g., SmarTone Macau and SmarTone HK might need to upgradetheir systems to support translation type if it is not currentlysupported.

[0211] Private Connection

[0212] Another option, that does not require a translation type, is aprivate connection option. This option is illustrated in FIG. 6 as anembodiment 600 in which an SPRS node 606 has a private SS7 connection toboth a SmarTone HK GMSC 602B, and a SmarTone Macau GMSC 602A. Theprivate connection can be a leased line from an IPLC provider. Theembodiment further includes an STP 604A and an STP 604B.

[0213] The SPRS node 606 can be physically located in SmarTone HK orSmarTone Macau. If the node is located in SmarTone Macau, it will allowSmarTone Macau to maintain and control the node and extend it for futureuse (e.g. piggybacking an alternative operator for roaming extension) onthe same node. However depending on available resources, it might bebetter to locate the node in SmarTone HK. No matter where the SPRS nodeis located, there are two SPCs associated with the node. One SPC is inthe SPC space of Hong Kong and the other SPC is in the SPC space ofMacau.

[0214] SmarTone HK assigns a pool of SmarTone HK-GTs to the SPRS node.The size of the pool is the same as the number of HLRs and SMSCs inSmarTone Macau. SmarTone Macau-GMSC is configured in its GTT in such away that all CdPA destined for international Gts (that have no roamingrelationships with SmarTone Macau) are routed through the SPRS withoutchanging the routing indicator (that is, still routing on GT).

[0215] SmarTone HK-GMSC configures its GTT in such a way that all CdPAdestined for all the SmarTone HK-GTs assigned to the SPRS and allCdPA/MGT in the special range of IMSI (e.g. 454-06-09-x) assigned toSmarTone Macau are routed through the PRS without changing the routingindicator (that is, still routing on GT).

[0216] The SPRS node retains the routing indicator on the GT. Whenreceiving a message from the SmarTone Macau side, the SPRS modifies theCgPA to its corresponding SmarTone HK GT, and send the message to theSmarTone HK GMSC. When receiving a message from the SmarTone HK side,the SPRS modifies the CdPA (e.g. SmarTone HK-MGT, SmarToneHK-GT-FOR-SmarTone Macau-HLR, SmarTone HK-GT-FOR-SmarTone Macau-SMSCetc) to its corresponding SmarTone Macau GT (e.g. SmarTone Macau-MGT,SmarTone Macau-HLR, SmarTone Macau-SMSC) and sends the message to theSmarTone Macau GMSC.

[0217] An advantage of this approach is that there is no requirement fora translation type, and there is no need to negotiate with REACH forspecial routing. However there might be a need to involve another IPLCprovider to interconnect the SPRS node to both SmarTone HK and Macaunetworks.

[0218] Global Title Modification

[0219] In this option, with reference to FIG. 7, SmarTone Macau andSmarTone HK have global title modification support. The SPRS node 706 isphysically located in SmarTone Macau, which is responsible for assigninga SPC (Signal Point Code) to the SPRS node 706. This allows SmarToneMacau to maintain and control the SPRS node and extend it for future use(e.g. piggybacking an alternative operator for roaming extension).

[0220] SmarTone HK assigns a pool of SmarTone HK-GTs to the SPRS node706. The size of the pool is the same as the number of HLRs and SMSCs inSmarTone Macau. The SmarTone Macau GMSC 702B is configured in its GTT insuch a way that all CdPA destined for international GTs are routedthrough the SPRS 706 without changing the routing indicator (that is,still routing on GT).

[0221] The SmarTone HK GMSC702A is configured in its GTT in such a waythat all CdPA destined for all the SmarTone HK-GTs assigned to the SPRS,and all CdPA/MGT in the special range of IMSI (e.g. 454-06-09-x)assigned to SmarTone Macau, are modified to the corresponding SmarToneMacau GTs without changing the routing indicator (that is, still routingon GT). Here, the SmarTone HK GMSC 702A supports global titlemodification. The SPRS node 706 retains the routing indicator on GT. Toavoid looping, the SmarTone Macau GMSC 702B also has the capability oflooking at CgPA GT for translation first. For any SCCP messages with aCgPA as a SmarTone HK GT, the SmarTone Macau GMSC 702B routes themessage through REACH, e.g, through STPs 704.

[0222] When a SCCP message does not have a CgPA of SmarTone HK, and hasa CdPA as an international GT that has no roaming relationship withSmarTone Macau, the SmarTone Macau GMSC routes the message to the SPRS706. The SPRS 706 modifies the CgPA to its corresponding SmarTone HK GT,possibly modifying MAP parameters, and sends the message back to theSmarTone Macau GMSC 702B.

[0223] Alternatively, SmarTone Macau has local translation type support.For any international CdPA GT that does not have a roaming relationshipwith SmarTone Macau, and the translation type is 0, SmarTone Macau GMSCwill route the message to the SPRS 706. The SPRS 706 modifies thecalling GT, possibly the MAP parameters, and sends the message back tothe SmarTone Macau GMSC 702B with a previously agreed non-zerotranslation type (e.g. 31). SmarTone Macau GMSC 702B configures its GTTto route the message to the REACH STP 704 with translation type 0,without changing the routing indicator.

[0224] In both alternatives, it is assumed REACH will not reject SCCPmessages with CgPA GTs from those of SmarTone HK on entering the REACHSTP that connects to the Macau side.

[0225] An advantage of this approach is it relatively simple connection,and the fact that no private connection is needded. The GT modificationsupport is provided by the SmarTone HK switch. Other support provided bythe SmarTone Macau switch is local translation type support, or GTTsupport for CgPA with preference over CdPA. It is assumed that REACHdoes not block messages with a SmarTone HK GT entering its Macau sideSTP.

[0226] GT Prefix

[0227] This approach is based on Mobile Number Portability (MNP), whichmodifies the called address by prefixing it with a routing number. Thisoption is also appropriate for the embodiment 700 of FIG. 7. SmarTone HKassigns a pool of SmarTone HK-GTs to the SPRS node 706. The size of thepool is the same as the number of HLRs and SMSCs in SmarTone Macau. TheSmarTone Macau-GMSC 702B is configured in its GTT in such a way that allCdPA destined for international GTs are routed through the SPRS 706without changing the routing indicator (that is, still routing on GT).

[0228] The SmarTone HK-GMSC 702A is configured in its GTT in such a waythat all CdPA destined for all the SmarTone HK-GTs assigned to the SPRS706, and all CdPA/MGT in the special range of IMSI (e.g. 454-06-09-x)assigned to SmarTone Macau, are modified to the corresponding SmarToneMacau GTs without changing the routing indicator (that is, still routingon GT). Here the SmarTone HK GMSC 702A supports global titlemodification.

[0229] The GTT modification on MGT (e.g. 454-06-09-X) also include a aspecial range indicator (e.g., 09 as before, or something different).For example, 454-06-09-X=>455-00-09-X. The SmarTone Macau GMSC 702B isconfigured to route the special (455-00-09-X) IMSI range through theSPRS node 706. The SPRS 706 strips the “09” and modifies the MAPparameters if necessary. The special IMSI range 455-00-09 is notprovisioned at the SmarTone Macau HLR.

[0230] When receiving a SCCP message that has a CdPA as an internationalGT that has no roaming relationship with SmarTone Macau, the SmarToneMacau GMSC routes the message to the SPRS node 706. The SPRS modifiesthe CdPA by prefixing it with a corresponding SmarTone HK GT dedicatedfor the SPRS function, possibly modifying MAP parameters and sends themessage back to the SmarTone Macau GMSC. To solve any possible maximumlength problem, the numbering plan is changed to GENERIC. It is assumedREACH will not reject SCCP messages with numbering plan as GENERIC. Todistinguish between E164 and E214/212 numbering plans, a differentprefix of a SmarTone HK GT for each is used to denote the SPRS node 706.

[0231] The SmarTone HK-GMSC 702A is configured in its GTT in such a waythat that the generic numbering plan-based special prefix is stripped,and the corresponding numbering plan identifier for the special prefixis assigned in the modified CdPA GT. Here again SmarTone HK GMSC 702Asupports global title modification.

[0232] This approach includes relatively simple connection, and does notrequire negotiation with REACH, or a private connection. GT modificationsupport is provided by the SmarTone HK switch. Local translation typesupport is provided by the SmarTone Macau switch, or GTT support forCgPA with preference over CdPA. Finally this approach assumes that REACHdoes not block messages with a SmarTone HK GT entering its Macau sideSTP 704B.

[0233] SPRS at both Networks

[0234] In this approach, illustrated by embodiment 800 of FIG. 8, thereis an SPRS node 806 in both SmarTone Macau and SmarTone HK. Each side isresponsible for assigning an SPC for its SPRS node 806. SmarTone HKassigns the same pool of SmarTone HK-GTs to both SPRS nodes 8-6A and806B. The size of the pool is the same as the number of HLRs and SMSCsin SmarTone Macau.

[0235] The SmarTone Macau-GMSC 806B is configured in its GTT in such away that SCCP messages of all CdPA destined for international GTs thathave no roaming relationships with SmarTone Macau are routed through itsside of SPRS node without changing the routing indicator (that is, stillrouting on GT).

[0236] SmarTone HK-GMSC802A is configured in its GTT in such a way thatall CdPA destined for all the SmarTone HK-GTs (for example, two GTs inone embodiment) assigned to SPRS, and all CdPA/MGT in the special rangeof IMSI (e.g. 454-06-09-x), assigned to SmarTone Macau are routedthrough its side of SPRS without changing the routing indicator (thatis, still routing on GT).

[0237] Each SPRS node 806 retains the routing indicator on GT. Whenreceiving a message from the SmarTone Macau GMSC, the Macau SPRS 806Bputs the original CdPA in a private MAP IE (information element) orencapsulate the original message in a FSMS message, modifies the CdPA toits corresponding SmarTone HK GT of SPRS, and sends the message back tothe SmarTone Macau GMSC 802B.

[0238] When receiving a message from the SmarTone HK GMSC 802A, theSmarTone HK SPRS 806A modifies the CdPA (e.g. SmarTone HK-MGT, SmarToneHK-GT-FOR-SmarTone Macau-HLR, SmarTone HK-GT-FOR-SmarTone Macau-SMSC) toits corresponding SmarTone Macau GT (e.g. SmarTone Macau-MGT, SmarToneMacau-HLR, SmarTone Macau-SMSC) and sends the message back to theSmarTone HK GMSC. However if the CdPA is intended for itself in the SCCPmessage, the SmarTone HK SPRS node 806A picks up the original CdPA fromthe private MAP IE or encapsulated FSMS message, and sets it as the newCdPA address of the SCCP message, possibly modifying other MAPparameters before sending back to the SmarTone HK GMSC 802A.

[0239] An advantage of this approach is it relatively simple connectionsand configurations. In addition, no special switch features such as TT,GT modifications etc, are needed. There is further no need for REACH orprivate connection. Two SPRS functions rather than one are required forthis approach. However, the hardware is not that expensive, and theoperators may not need pay for additional software licenses.

[0240] Detailed Scenarios

[0241] The following section lists messages that pass through theproposed SPRS node. The SPRS node can be physically located in SmarToneHK or SmarTone Macau, or in both depending on the routing optionsadopted as described earlier. Also described, with examples, aretransformations that the SPRS node performs on the messages, for examplein the addressing, and if applicable, in the application payload in someMAP messages.

[0242] In various embodiments, all inter-PLMN MAP messages are trapped,transformed and/or re-routed by the SPRS node.

[0243] For the information in this section, it is assumed thatrouting/translation tables at the SmarTone Macau will route all SCCPmessages for international numbers of those mobile networks that do nothave a roaming relationship with SmarTone Macau to the SPRS node usingone of the routing options described earlier. It is also assumed thatrouting/translation tables at the SmarTone HK will route all SCCPmessages for a special set of SmarTone HK GTs to the SPRS node whichrelays the messages to the real destination in SmarTone Macau networkusing one of the routing options described earlier.

[0244] Inbound Roamer Registration/Location Update

[0245] This section describes the messages related toregistration/location update of UK subscribers roaming in SmarToneMacau. Table 1 describes a MAP_UPDATE_LOCATION message of oneembodiment. Here there is a static mapping of each SmarTone Macau VLRand VMSC to a SmarTone HK GT. This mapping is maintained at the SPRSnode. TABLE 1 Message sender/ receiver Message content Remarks SmarToneSCCP Called Address: Macau VLR to Global Title: 44-181-123456 MGTderived from IMSI SmarTone SSN: 6 HLR Macau GMSC SCCP Calling Address:Global Title: 853-624-333333 GT of SmarTone Macau VLR SSN: 7 VLR MAPlevel parameters: IMSI: 234-15-123456 IMSI of Orange UK subscriber MSCaddress 853-624-444444 E.164 number of serving MSC VLR number853-624-333333 E.164 number of serving VLR SmarTone Same as above Directall GTs of any non-roaming Macau GMSC to partner of SmarTone Macautowards SPRS SPRS SPRS to SCCP Called Address: SmarTone HK Global Title:44-181-123456 MGT derived from IMSI GMSC SSN: 6 HLR SCCP CallingAddress: Global Title: 852-620-005469 SmarTone HK GT of SPRScorresponding to SmarTone Macau VLR SSN: 7 VLR (to make UK HLR thinkrequest is coming from a SmarTone HK VLR) MAP level parameters: IMSI:234-15-123456 IMSI of UK subscriber MSC address 852-620-005467 Convertto a corresponding SmarTone HK address VLR number 852-620-005469 Convertto a corresponding SmarTone HK address SmarTone HK Same as above NormalRouting based on GMSC to UK Translation Type 0 GMSC/HLR

[0246] Table 2 describes a MAP_UPDATE_GPRS_LOCATION message of oneembodiment. The registration sequence begins with theMAP_UPDATE_GPRS_LOCATION message. This message is sent by the servingSmarTone Macau SGSN to the UK HLR. Here there is a static mapping ofeach SmarTone Macau SGSN number and IP address to a SmarTone HK GT andaddress. This mapping is maintained at the SPRS node. The mapping can bedynamically created and remain static afterwards. TABLE 2 Messagesender/ receiver Message content Remarks SmarTone SCCP Called Address:Macau SGSN to Global Title: 44-181-123456 MGT derived from IMSI SmarToneSSN: 6 HLR Macau GMSC SCCP Calling Address: Global Title: 853-624-333333GT of SmarTone Macau SGSN SSN: 95 SGSN hex MAP level parameters: IMSI:234-15-123456 IMSI of Orange UK subscriber SGSN address TLV-IP-MacauType, length, Ipv4/v6 address SGSN number 853-624-333333 E.164 number ofSGSN SmarTone Same as above Direct all GTs of any non-roaming Macau GMSCto partner of SmarTone Macau towards SPRS SPRS SPRS to SCCP CalledAddress: SmarTone HK Global Title: 44-181-123456 MGT derived from IMSIGMSC SSN: 6 HLR SCCP Calling Address: Global Title: 852-620-005469SmarTone HK GT of SPRS corresponding to SmarTone Macau SGSN SSN: 95 SGSN(to make UK HLR think request is coming from a SmarTone HK SGSN) MAPlevel parameters: IMSI: 234-15-123456 IMSI of UK subscriber SGSN addressTLV-IP-HK Convert to a corresponding SmarTone HK address SGSN number852-620- Convert to a corresponding 005469 SmarTone HK address SmarToneHK Same as above Normal Routing based on GMSC to UK Translation Type 0GMSC/HLR

[0247] Table 3 describes a MAP_INSERT_SUBSCRIBER_DATA message of oneembodiment. This message is sent by the UK HLR in response to theMAP_UPDATE_GPRS_LOCATION or MAP_UPDATE_LOCATION request received fromthe SmarTone Macau_VLR/SGSN (which the UK HLR thinks was sent by aSmarTone HK VLR/SGSN). The role of SPRS for this message is to identifythat this message needs to go to the SmarTone Macau VLR/SGSN, and toroute it accordingly by changing the SCCP parameters. SGSN and VLR areconsidered together in the following.

[0248] In the case of Called Address being the SGSN, each APN cannot bechanged since SGSN needs that to verify if the MS is allowed to accessthe APN when it tries to create a PDP context with that APN. Howeverwhen the ST Macau SGSN issues a DNS request on APN, the DNS server isconfigured to return SPRS IP address for any APN that has no entry. TheSPRS has partial SGSN/GGSN functionality to support Gp interfacespecifically. When ST Macau SGSN tries to create a PDP context withSPRS—the first leg of tunnel, SPRS uses the APN in the create request toissue another DNS request in the domain of ST HK, which would return theUK GGSN. The SPRS then establishes a second leg of PDP context with theUK GGSN. The tunnel ID and IMSI, or charging ID, can be relayed over thelegs and are used to identify the relaying forward and backward betweenthe two legs of GTP tunnels. In this case, the SPRS then functions as aSTHK GGSN to STMC SGSN, and a STHK SGSN to UK GGSN. TABLE 3 Messagesender/ receiver Message content Remarks UK HLR/GMSC SCCP CalledAddress: to SmarTone HK Global Title: 852-620-005469 SmarTone HK GT ofSPRS GMSC corresponding to SmarTone Macau SSN: 7/95 VLR/SGSN VLR/SGSNSCCP Calling Address: Global Title: 44-181-444444 GT of UK HLR SSN: 6HLR MAP level parameters: IMSI: 234-15-123456 IMSI of Orange UKsubscriber MSISDN 44-181-654321 MSISDN of UK subscriber (Either IMSI orMSISDN will be present. MSISDN in case of a location update; IMSI inother cases (e.g. operator determined barring).) UK GPRS subscriptiondata, using PDP In case of SGSN being the called context including type,address, APN address Uk-apn.uk.gprs UK APN SmarTone HK Same as aboveSmarTone HK GMSC routes the GMSC to SPRS message to the SPRS based onthe SPRS GT SPRS to SCCP Called Address: SmarTone Global Title:853-624-333333 GT of SmarTone Macau Macau GMSC VLR/SGSN (which SPRS hadestablished from the static mapping) SSN: 7/95 VLR/SGSN SCCP CallingAddress: Global Title: 44-181-444444 GT of UK HLR SSN: 6 HLR MAP levelparameters: IMSI: 234-15-123456 IMSI of UK subscriber unchanged MSISDN:44-181-654321 MSISDN of UK subscriber unchanged Uk-apn.uk.gprs unchangedSmarTone Same as above Routing based on SmarTone Macau Macau GMSC toVLR/SGSN GT SmarTone Macau VLR/SGSN

[0249] Table 4 describes a MAP_INSERT_SUBSCRIBER_DATA response of oneembodiment. This message is sent by the SmarTone Macau VLR in responseto the Insert_Subscriber_Data request sent by the UK HLR. The SPRSmodifies this message such that the UK HLR thinks it is coming from aSmarTone HK VLR/SGSN. TABLE 4 Message sender/ receiver Message contentRemarks SmarTone SCCP Called Address: Macau GMSC Global Title:44-181-444444 This time, the MGT is to SPRS not derived from IMSI butfrom the SCCP Calling Address in the insert_sub_data msg SSN: 6 HLR SCCPCalling Address: Global Title: 853-624-333333 GT of SmarTone Macau SSN:7/95 VLR/SGSN VLR/SGSN MAP level parameters: None. SPRS to SCCP CalledAddress: SmarTone HK Global Title: 44-181-444444 GT of UK HLR GMSC SSN:6 HLR SCCP Calling Address: Global Title: 852-620-005469 SmarTone HK GTof SPRS corresponding to SmarTone Macau SSN: 7/95 VLR/SGSN VLR/SGSN MAPlevel parameters: None. SmarTone HK Same as above Normal routing GMSC toUK based on UK HLR GMSC/HLR GT

[0250] Table 5 describes a MAP_UPDATE_LOCATION orMAP_UPDATE_GPRS_LOCATION response of one embodiment. This message issent by the UK HLR in response to the update location or updateGPRS_location request sent by the SmarTone Macau VLR/SGSN. It is sentafter the Insert_Subscriber_Data sequence is completed. The SPRSmodifies this message so that it is sent to the SmarTone Macau VLR/SGSN.TABLE 5 Message sender/ receiver Message content Remarks UK HLR/GMSCSCCP Called Address: to SmarTone HK Global Title: 852-620-005469SmarTone HK GT of SPRS GMSC corresponding to SmarTone Macau SSN: 7/95VLR/SGSN VLR/SGSN SCCP Calling Address: Global Title: 44-181-444444 GTof UK HLR SSN: 6 HLR MAP level parameters: None. SmarTone HK Same asabove Normal Routing based on SmarTone GMSC to SPRS HK SPRS GT SPRS toSCCP Called Address: SmarTone Global Title: 853-624-333333 GT ofSmarTone Macau Macau GMSC SSN: 7/95 VLR/SGSN (saved earlier) VLR/SGSNSCCP Calling Address: Global Title: 44-181-444444 GT of UK HLR SSN: 6HLR MAP level parameters: None. SmarTone Same as above Normal routingbased on GT of Macau GMSC to SmarTone Macau VLR/SGSN VLR

[0251] Inbound Roamer Deregistration (Cancel Location)

[0252] The following section details messages and responses for thefollowing example scenario: a UK subscriber who had been roaming inSmarTone Macau has now registered in another network. The registrationin the SmarTone Macau network must be cancelled

[0253] Table 6 describes a MAP_CANCEL_LOCATION request of oneembodiment. The UK HLR sends a MAP_CANCEL LOCATION request to theSmarTone HK GT of SPRS, which identifies SmarTone Macau VLR as the realrecipient, and forwards the message accordingly. TABLE 6 Message sender/receiver Message content Remarks UK GMSC to SCCP Called Address:SmarTone HK Global Title: 852-620-005469 SmarTone HK GT of SPRS GMSCcorresponding to SmarTone Macau VLR/SGSN SSN: 7/95 VLR/SGSN SCCP CallingAddress: Global Title: 44-181-555555 GT of UK HLR SSN: 6 HLR MAP levelparameters: IMSI: 234-15-123456 IMSI of Orange UK subscriber SmarTone HKSame as above Normal routing based on SmarTone GMSC to SPRS HK GT ofSPRS SPRS to SCCP Called Address: SmarTone Global Title: 853-624-333333GT of SmarTone Macau Macau GMSC SSN: 7/95 VLR/SGSN VLR/SGSN SCCP CallingAddress: Global Title: 44-181-555555 GT of UK HLR SSN: 6 HLR MAP levelparameters: IMSI: 234-15-123456 IMSI of UK subscriber SmarTone Same asabove Normal Routing based on GT of Macau GMSC to VLR VLR

[0254] Table 7 describes a MAP_CANCEL_LOCATION response of oneembodiment. This message is sent by the SmarTone Macau VLR/SGSN to theUK HLR in response to the Location_Cancel message. The SPRS modifies itso that it appears to be sent by a SmarTone HK VLR. TABLE 7 Messagesender/ receiver Message content Remarks SmarTone SCCP Called Address:Macau GMSC Global Title: 44-181-555555 GT of UK HLR to SPRS SSN: 6 HLRSCCP Calling Address: Global Title: 853-624-333333 GT of SmarTone MacauVLR SSN: 7 VLR MAP level parameters: None. SPRS to SCCP Called Address:SmarTone HK Global Title: 44-181-555555 GT of UK HLR GMSC SSN: 6 HLRSCCP Calling Address: Global Title: 852-620-005469 SmarTone HK GT ofSPRS corresponding to the SmarTone Macau VLR SSN: 7 VLR MAP levelparameters: None. SmarTone HK Same as above Normal Routing GMSC to UKbased on TT = 0 GMSC/HLR

[0255] CAMEL messages such as IDP and Continue/Connect for inboundroamers are similarly relayed through the SPRS node. When inboundroamers from the UK register with Smartone Macau, any CAMEL SubscriptionInformation (CSI, either O-CSI, VT-CSI, GPRS-CSI etc) will not bemodified when the MAP-Insert Subscriber Data message is relayed from theUK HLR thru the SPRS to Smartone Macau VLR. This is because gsmSCF andgsmSSF address are relayed thru the SPRS anyway.

[0256]FIG. 9 is an illustration of an architecture 900 that supportsCAMEL. The architecture includes a home network 902, a visited network904, and an interrogating network 906. The home network 902 includes anHLR 908 and a gsmSCF 910. The visited network includes a VLR 914, agsmSSF 912B, and an MSC 916. The interrogating network includes a GMSC918 and a gsmSSF 912A. The referenced elements communicate as indicated(with reference to the list of acronyms).

[0257] For CAP messages such as IDP that are relayed thru the SPRS node,the VMSC/VLR address, if present, is modified to the corresponding SPRSaddress.

[0258] Outbound Roamer Registration/Location Update

[0259] This section describes the messages related toregistration/location update of SmarTone Macau subscribers roaming inUK.

[0260] Basically, for outbound roamers, all SCCP CdPA, IMSI, GGSNaddress, GGSN number, SGSN address, gsmSCF number, etc in MAP,Camel/CAP, and GPRS messages are modified into the corresponding SPRSaddress/number. It is not necessary to modify SCCP CgPA address, SGSNnumber or visited network numbers since they will have to be relayedthru SPRS node anyway.

[0261] Table 8 describes a MAP_UPDATE_LOCATION message of oneembodiment. The registration sequence begins with theMAP_UPDATE_LOCATION message. This message is sent by the serving VLR tothe HLR. TABLE 8 Message sender/ receiver Message content Remarks UKVLR/GMSC SCCP Called Address: to SmarTone HK Global Title:852-620-09-12345 MGT derived from IMSI GMSC SSN: 6 HLR SCCP CallingAddress: Global Title: 44-181-000001 UK VLR GT SSN: 7 VLR MAP levelparameters: IMSI: 454-06-09-12345 IMSI is a SmarTone HK IMSI (454- 06)but allocated to a SmarTone Macau subscriber (because of the 09) MSCaddress 44-181-000002 E.164 number of serving MSC VLR number44-181-000001 E.164 number of serving VLR SmarTone HK Same as aboveSmarTone HK GMSC routes the GMSC to SPRS message to the SPRS (based onthe 09 in the called address), without any change SPRS to SCCP CallingAddress: SmarTone Global Title: 44-181-000001 UK VLR id Macau SSN: 7 VLRGMSC/HLR SCCP Called Address: Global Title: 852-624-12345 ConvertSmarTone HK MGT to SmarTone Macau MGT SSN: 6 HLR MAP level parameters:IMSI: 455-00-12345 Convert SmarTone HK IMSI to SmarTone Macau IMSI MSCaddress 44-181-000002 UK MSC address unchanged VLR number 44-181-000001UK VLR number unchanged

[0262] Table 9 describes a MAP_UPDATE_GPRS_LOCATION message of oneembodiment.

[0263] The registration sequence begins with theMAP_UPDATE_GPRS_LOCATION message. This message is sent by the servingSGSN to the HLR. A UK SGSN address is changed to an ST HK SGSN addressto take care the case of network-initiated PDP context activation whenSRI-GPRS is issued to ST Macau HLR by ST Macau GGSN. Fornetwork-initiated PDP context, the GGSN will inform SPRS address withIMSI. The SPRS can then use the IMSI information to find the true SGSNaddress to send notification to. TABLE 9 Message sender/ receiverMessage content Remarks UK VLR/GMSC SCCP Called Address: to SmarTone HKGlobal Title: 852-620-09-12345 MGT derived from IMSI GMSC SSN: 6 HLRSCCP Calling Address: Global Title: 44-181-000001 UK SGSN GT SSN: 95SGSN MAP level parameters: IMSI: 454-06-09-12345 IMSI is a SmarTone HKIMSI 454- 06) but allocated to a SmarTone Macau subscriber (because ofthe 09) SGSN address TLV-IP-UK Type, length, value of IP address of SGSNSGSN number 44-181-000001 E.164 number of serving SGSN SmarTone HK Sameas above SmarTone HK GMSC routes the GMSC to SPRS message to the SPRS(based on the 09 in the called address), without any change SPRS to SCCPCalling Address: SmarTone Global Title: 44-181-000001 UK SGSN id MacauSSN: 95 SGSN GMSC/HLR SCCP Called Address: Global Title: 852-624-12345Convert SmarTone HK MGT to SmarTone Macau MGT SSN: 6 HLR MAP levelparameters: IMSI: 455-00-12345 Convert SmarTone HK IMSI to SmarToneMacau IMSI SGSN address TLV-IP-HK UK SGSN address changed to the SPRS IPaddress IMSI and UK SGSN address can be saved SGSN number 44-181- UKSGSN number unchanged 000001

[0264] Table 10 describes a MAP_INSERT_SUBSCRIBER_DATA request of oneembodiment. Upon receiving an MAP_UPDATE_LOCATION message from the UKVLR or an MAP_UPDATE_GPRS_LOCATION message from the UK SGSN, theSmarTone Macau HLR sends a MAP_INSERT_SUBSCRIBER_DATA message to UKVLR/SGSN. The message goes through the SmarTone HK SPRS. The SPRSmodifies this message so that it gets correctly routed to the UKVLR/SGSN. Here, SmarTone Macau configures their STP GTT function toroute all destinations of non-roaming partners through the SmarTone HKSPRS. When outroamer MS and UK SGSN establishes the first leg of PDPcontext, the DNS of STHK-APN maps to the SPRS node, which can thenestablish the second leg of PDP context with the STMC GGSN with thecorresponding STMC-APN. Again, the SPRS can use a tunnel ID to relatethe two legs. The charging ID can also be relayed. The APN from the HLRdoes not have the operator name. As long as the sponsoring operator doesnot use the same APN names as the sponsored operator, there is no needto change the STMC APN into STHK APN. TABLE 10 Message sender/ receiverMessage content Remarks SmarTone SCCP Called Address: Macau GlobalTitle: 44-181-000001 UK VLR/SGSN id HLR/GMSC to SSN: 7/95 VLR/SGSN SPRSTranslation Type: 0 SCCP Calling Address: Global Title: 852-624-555555Global Title (E.164) of SmarTone Macau HLR SSN: 6 HLR MAP levelparameters: IMSI: 455-00-12345 IMSI will not be included in aninsert_sub_data message that is part of a location update. It will onlybe included if the msg is initiated by HLR (as a result of asubscription change). MSISDN: 852-624-111111 SPRS to SCCP CalledAddress: SmarTone HK Global Title: 44-181-0000001 UK VLR/SGSN id GMSCSSN: 7/95 VLR/SGSN SCCP Calling Address: Global Title: 852-620-005469Change SmarTone Macau HLR GT to SmarTone HK SPRS GT that corresponds toSmarTone Macua HLR SSN: 6 MAP level parameters: IMSI: 454-06-09-12345Modify IMSI if present MSISDN: 852-624-111111 Keep MSISDN unchanged AllCSI: gsmSCF => SPRS Change all gsmSCF address in any Camel subscriptioninformation to the SPRS node APN: APN-STMC => APN-STHK Change each STMCAPN into the corresponding STHK APN. The correspondence mapping isestablished statically beforehand SmarTone HK Same as above Routingbased on the normal routing GMSC to UK table (Translation Type 0)GMSC/VLR

[0265] Table 11 describes a MAP_INSERT_SUBSCRIBER_DATA response of oneembodiment. This message is sent by the UK VLR to the SmarTone HK SPRS(which it thinks is the SmarTone HK HLR) to acknowledge theInsert_Subscriber_Data request. The SPRS must identify the SmarToneMacau HLR as the final recipient and must route the message accordingly.TABLE 11 Message sender/ receiver Message content Remarks UK VLR/GMSCSCCP Called Address: to SmarTone HK Global Title: 852-620-005469 Thistime, the MGT is not derived GMSC from IMSI but from the SCCP CallingAddress in the insert_sub_data msg SSN: 6 HLR SCCP Calling Address:Global Title: 44- UK VLR/SGSN id 100000001 SSN: 7/95 VLR/SGSN MAP levelparameters: None. SmarTone HK Same as above NORMAL ROUTING BASED GMSC toSPRS ON SPRS GT (AT THIS POINT THE GMSC DOES NOT KNOW THIS MESSAGE ISFOR SMARTONE MACAU). SPRS to SCCP Called Address: SmarTone Global Title:852-624-555555 SmarTone Macau HLR GT Macau SSN: 6 HLR GMSC/HLR SCCPCalling Address: Global Title: 44- UK SGSN id 100000001 SSN: 7/95VLR/SGSN MAP level parameters: None.

[0266] Table 12 describes a MAP_UPDATE_LOCATION orMAP_UPDATE_GPRS_LOCATION response of one embodiment. This message is anacknowledgement to the Update_Location or Update_GPRS_Location request.It is sent by the SmarTone Macau HLR to the UK VLR. SmarTone HK SPRSmust modify it to make it look as if it was being sent by the SmarToneHK HLR. Here SmarTone Macau configures its STP GTT function to route alldestination of non-roaming partners through the SmarTone HK SPRS. TABLE12 Message sender/ receiver Message content Remarks SmarTone SCCP CalledAddress: Macau Global Title: 44-181-000001 GT of UK VLR HLR/GMSC to SSN:7/95 VLR/SGSN SPRS SCCP Calling Address: Global Title: 852-624-555555SmarTone Macau HLR GT SSN: 6 HLR MAP level parameters: None. SPRS toSCCP Called Address: SmarTone HK Global Title: 44-181-000001 UK VLR/SGSNid GMSC SSN: 7/95 VLR/SGSN SCCP Calling Address: Global Title:852-620-005468 SmarTone HK GT of SPRS corresponding to SmarTone MacauSSN: 6 HLR MAP level parameters: None. HLR SmarTone HK Same as aboveNormal Routing (Translation Type 0) GMSC to UK GMSC/VLR

[0267] Outbound Roamer Deregistration (Cancel Location)

[0268] When a SmarTone Macau subscriber who had been roaming in the UKhas registered from another network (home network or any other network),they need to be deregistered from the UK VLR. This section describes themessages used for this, along with the role played by the SPRS.

[0269] Table 13 describes a MAP_CANCEL_LOCATION message of oneembodiment. The SmarTone Macau HLR sends a MAP_CANCEL_LOCATION messageto the UK VLR/SGSNN. The SPRS modifies this message to make it seem likeit was being sent by a SmarTone HK HLR. TABLE 13 Message sender/receiver Message content Remarks SmarTone SCCP Called Address: MacauGlobal Title: 44-181-000001 GT of UK VLR/SGSN HLR/GMSC to SSN: 7/95VLR/SGSN SPRS SCCP Calling Address: Global Title: 852-624-555555 GT ofSmarTone Macau HLR SSN: 6 HLR MAP level parameters: IMSI: 455-00-123456IMSI of SmarTone Macau subscriber SPRS to SCCP Called Address: SmarToneHK Global Title: 44-181-000001 GT of UK VLR/SGSNs GMSC SSN: 7/95VLR/SGSN SCCP Calling Address: Global Title: 852-620-005468 SmarTone HKGT of SPRS corresponding to SmarTone Macau SSN: 6 HLR MAP levelparameters: HLR IMSI: 454-06-09-12345 CONVERT SMARTONE MACAU IMSI TOSMARTONE HK IMSI SmarTone HK Same as above Normal Routing based on GMSCto UK Translation Type 0 GMSC/VLR

[0270] Table 14 describes a MAP_CANCEL_LOCATION response of oneembodiment. This message is sent by the UK VLR/SGSN to the SmarTone HKSPRS in response to the Location_Cancel message. The SPRS identifies itas intended for SmarTone Macau HLR and forwards it accordingly. CAMELmessages such as IDP and Continue/Connect for outbound roamers aresimilarly relayed thru the SPRS node. TABLE 14 Message sender/ receiverMessage content Remarks UK VLR/GMSC SCCP Called Address: to SmarTone HKGlobal Title: 852-620-005468 SmarTone HK GT of SPRS GMSC correspondingto SmarTone Macau HLR SSN: 6 HLR SCCP Calling Address: Global Title:44-181-000001 GT of UK VLR/SGSN SSN: 7/95 VLR/SGSN MAP level parameters:None. SmarTone HK Same as above Normal routing based on GT of SmarToneGMSC to SPRS HK GT of SPRS SPRS to SCCP Called Address: SmarTone GlobalTitle: 852-624-555555 GT of SmarTone Macau HLR Macau SSN: 6 HLR GMSC/HLRSCCP Calling Address: Global Title: 44-181-000001 GT of UK VLR/SGSN SSN:7/95 VLR/SGSN MAP level parameters: None.

[0271] Referring again to FIG. 9, for Smartone Macau outbound roamersregistering in the UK with Smartone HK IMSI, when theMAP-InsertSubscriberData is relayed thru the SPRS, the SPRS modifies allgsmSCF in any CSI to be a SPRS GT that corresponds to the gsmSCFaddress. This is different from the inbound roaming case in which no CSIinformation is modified by SPRS on UK inbound roamers registering inSmartone Macau.

[0272] The modification for the outbound roaming case is necessary sincethe UK has no roaming relationship with Smartone Macau.

[0273] Unlike the inbound roaming case, it is not necessary to modifyVMSC/VLR numbers in the CAP messages, such as IDP, from the visitingnetwork (e.g. UK) to the home network. However the IMSI is modified inthe CAP messages when they are relayed thru the SPRS node from UK to HKand then to Macau.

[0274]FIG. 10 is a diagram of a GPRS reference architecture 1000, whichshows the interface point between various network elements. Withreference also to the list of acronyms, the architecture includes acentral serving GPRS service node (SGS) 1014. The architecture furtherincludes several switching center, such as a mobile switching center1012, and a CAMEL switching center 1006. Two networks, a packet datanetwork 1008, and another network 1010 are shown. The other network 1010is, for example, a PLMN. More than two networks are possible in theartchitecture.

[0275] UK GPRS Roaming in Smartone Macau

[0276] Referring to FIG. 11, an embodiment 1100 is shown in which a UKsubscriber 1108 is roaming in SmarTone Macau, using SGSN 1102 ofSmarTone Macau. The embodiment 1100 further includes a GGSN 1104 of theOrange UK network, and a SmarTone HK SPRS 1106. The subscriber performsa PDP context activation with an APN. The ST Macau SGSN 1102 issues aDNS request on the APN; the DNS server is configured to return a SPRS1106 IP address as the GGSN 1104 for any APN that has no entry. The SPRS1106 has partial SGSN/GGSN functionality. When ST Macau SGSN 1102 triesto create a PDP context with SPRS 1106 (the first leg of tunnel), SPRS1106 uses the APN to issue another DNS request in the domain of ST HK,which would return the UK GGSN 1104. The SPRS 1106 then establishes asecond leg of PDP context with the UK GGSN 1104. The tunnel ID and IMSI,or charging ID, can be relayed over the second leg, and are used toidentify the relaying forward and backward between the two legs of GTPtunnels. In this case, the SPRS 1106 then functions as a STHK GGSN toSTMC SGSN and a STHK SGSN to UK GGSN 1104.

[0277] The IMSI of the PDP context activation remains the same acrossthe two bridged tunnels. Similar mechanism are applied formodifying/updating PDP context, and deleting PDP context.

[0278] GPRS Tunnelling Protocol is employed on the Gn interface in orderto tunnel user data between different GSNs (GPRS Support Nodes). Theprotocol supports both signalling and user data under one genericheader. It can be used with UDP (User Datagram Protocol) or TCP(Transmission Control Protocol) on the registered port 3386. The GTPversion is used only on UDP. The control plane protocol GTP-C (Control)uses registered port 2123 and the user plane protocol GTP-U (User) usesregistered port 2152.

[0279] When an UK inbound roamer is setting up a PDP context via a GTP-Cmessage or sending a PDP message using GTP-U using UK IMSI, based on theversion of GPRS protocol, the UDP message will reach SPRS at thecorresponding port. The SPRS examines the message and modify the sourceIP address to be itself, destination IP address to be the real UK GGSNaddress. Other parameters can stay the same. The reverse path does thereverse.

[0280] INCOMING CALL TO A UK SUBSCRIBER ROAMING IN SmarTone Macau Thecall (ISUP IAM) first gets routed to the UK GMSC, which makes an SRIquery to the UK HLR. The UK HLR can respond to the SRI only after it hasqueried the SmarTone Macau VLR (which it thinks is the SmarTone HK VLR)with a PRN and has obtained an MSRN.

[0281] Table 15 describes a MAP_PROVIDE_ROAMING_NUMBER request of oneembodiment. This message is sent by the UK HLR to the SmarTone HK GT ofSPRS. The SPRS must forward it to the SmarTone Macau VLR. TABLE 15Message sender/ receiver Message content Remarks UK GMSC to SCCP CalledAddress: SmarTone HK Global Title: 852-620-005469 SmarTone HK GT of SPRSGMSC corresponding to SmarTone Macau VLR SSN: 7 VLR SCCP CallingAddress: Global Title: 44-181-555555 GT of UK HLR SSN: 6 HLR MAP levelparameters: IMSI: 234-15-123456 IMSI of UK subscriber MSISDN:44-181-654321 MSISDN of UK subscriber SmarTone HK Same as above Normalrouting based on SmarTone GMSC to SPRS HK GT of SPRS SPRS to SCCP CalledAddress: SmarTone Global Title: 853-624-333333 GT of SmarTone Macau VLRMacau GMSC (SPRS must have it in a table) that corresponds to theSmarTone HK GT of SPRS SSN: 7 VLR SCCP Calling Address: Global Title:44-181-555555 GT of UK HLR SSN: 6 HLR MAP level parameters: IMSI:234-15-123456 IMSI of UK subscriber MSISDN: 44-181-654321 MSISDN of UKsubscriber SmarTone Same as above Normal routing based on GT of MacauGMSC to SmarTone Macau VLR VLR

[0282] Table 16 describes a MAP_PROVIDE_ROAMING_NUMBER response of oneembodiment. This message is sent by the SmarTone Macau VLR to the UK HLRin response to the PRN request. The SPRS acts as a proxy VLR with aSmarTone HK GT. TABLE 16 Message sender/ receiver Message contentRemarks SmarTone SCCP Called Address: Macau Global Title: 44-181-555555GT of UK HLR (copied from SCCP VLR/GMSC to called number in PRN request)SPRS SSN: 6 HLR SCCP Calling Address: Global Title: 853-624-333333 GT ofSmarTone Macau VLR SSN: 7 VLR MAP level parameters: No change needed(main parameter is the MSRN) SPRS to SCCP Called Address: SmarTone HKGlobal Title: 44-181-555555 GT of UK HLR GMSC SSN: 6 HLR SCCP CallingAddress: Global Title: 852-620-005469 SmarTone HK GT of SPRScorresponding to SmarTone Macau SSN: 7 VLR VLR SmarTone HK Same as aboveNormal routing based on GT of UK GMSC to UK HLR GMSC/HLR

[0283] The MSRN may be changed by the SPRS. If the MSRN is not changed,then call routing will be directly from UK to Macau. If it is changed,then call routing will be from UK to HK, and then to Macau. The ST HKswitch will either use ISUP loopback, or IN to route the call on thespecially ranged MSRN of SH HK to the SPRS platform, which then willredirect the call onto the real MSRN. One advantage is that IDD markupon the roaming rerouted call by UK can be always applied on top of routeto HK where UK has a roaming partnership. However, the call will beindirectly routed between UK and Macau via HK. If the distance betweenHK and Macau is large, it might be confusing and expensive. One approachto avoiding this possibility is for HK and Macau to set up specialleased lines for such indirect calls. In addition, rerouted calls to HKshould be cheaper than rerouted calls to Macau, so outbound roamers ofUK don't get overcharged. To recover the indirect routing cost, HK/Macaucan have a different roaming rates for a mobile terminated call atMacau.

[0284] If MSRN is not changed, the rerouting charge between thesponsoring country and sponsored country should be similar to avoidlosing money for UK operator or overcharging the outbound roamer. Thisturns out to be the case for HK and Macau.

[0285] Macau GPRS Roaming in UK

[0286] Referring to FIG. 12, an embodiment 1200 is shown in which aSmarTone Macau subscriber 1208 is roaming in Orange UK, using SGSN 1202of Orange UK. The embodiment 1200 further includes a GGSN 1204 of theSmarTone Macau network, and a SmarTone HK SPRS 1206. PDP tunnels 1210Aand 1210B are also shown. The handset selects the ST HK IMSI and ST PDPprofile. The subscriber 1208 performs a PDP context activation with anAPN. The UK SGSN 1202 issues DNS request on the APN, the DNS server mustbe configured to return SPRS IP address as the GGSN for such an APN. TheSPRS 1206 has partial SGSN/GGSN functionality. When UK SGSN 1202 triesto create a PDP context with SPRS (the first leg of the tunnel), theSPRS 1206 first finds the corresponding ST Macau APN and uses thetranslated APN to issue another DNS request in the domain of ST HK whichreturns the ST-Macau GGSN. The SPRS 1206 then establishes a second legof PDP context with the ST-Macau GGSN 1204. The tunnel ID and IMSI orcharging ID can be relayed over the second leg, and are used to identifythe relaying forward and functions as a STHK GGSN to the UK SGSN 1202,and a STMC GGSN to STHK SGSN.

[0287] The tunnel ID for the first tunnel has the ST HK IMSI, while thetunnel ID for the second tunnel has the ST Macau IMSI. Otherinformation, such as NSAPI, Charging ID, PDP address etc can be relayedthru the SPRS node 1296.

[0288] GPRS Tunnelling Protocol is employed on the Gn interface in orderto tunnel user data between different GSNs (GPRS Support Nodes). Theprotocol supports both signalling and user data under one genericheader. It can be used with UDP (User Datagram Protocol) or TCP(Transmission Control Protocol) on the registered port 3386. The GTPversion one is used only on UDP. The control plane protocol GTP-C(Control) uses registered port 2123, and the user plane protocol GTP-U(User) uses registered port 2152.

[0289] When a Smartone Macau outbound roamer is setting up a PDP contextvia a GTP-C message or sending a PDP message using GTP-U using SmartoneHK IMSI, based on the version of GPRS protocol, the UDP message willreach SPRS at the corresponding port. The SPRS examines the message andmodifies the source IP address to be itself, destination IP address tobe the real Smartone Macau GGSN address, and (if present) APN to be theone at Smartone Macau that corresponds to the APN from Smart HK IMSI. Italso changes TID Smartone HK IMSI to its corresponding Smartone MacauIMSI. The reverse path does the reverse.

[0290] The mapping of APN Macau with APN HK and the corresponding GGSNcan be maintained locally via a DB, or configuration file, or externalDNS or Directory service.

[0291] Incoming Call to a Smartone Macau Subscriber Roaming in UK

[0292] All calls to a SmarTone Macau subscriber roaming in UK are firstrouted to the SmarTone Macau GMSC through an ISUP IAM. The GMSC thenqueries the HLR by means of a MAP_SEND_ROUTING_INFORMATION request. Thismessage is within the SmarTone Macau PLMN. However, in order to respondto the SRI, the SmarTone Macau HLR must query the UK VLR for an MSRN.This is done by sending a MAP_PROVIDE_ROAMING_NUMBER message. Thismessage and its response go across PLMNs and hence are of concern to theSPRS.

[0293] Table 17 describes a MAP_PROVIDE_ROAMING_NUMBER request of oneembodiment. This message is sent by the SmarTone Macau HLR to the UKVLR. The SPRS makes it look like a PRN request coming from a SmarTone HKHLR TABLE 17 Message sender/ receiver Message content Remarks SmarToneSCCP Called Address: Macau GMSC to Global Title: 44-181-333333 GT of UKVLR SPRS SSN: 7 VLR SCCP Calling Address: Global Title: 853-624-555555GT of SmarTone Macau HLR SSN: 6 HLR MAP level parameters: IMSI:455-00-12345 IMSI of SmarTone Macau subscriber MSISDN: 852-624-654321MSISDN of SmarTone Macau subscriber unchanged if present SPRS to SCCPCalled Address: SmarTone HK Global Title: 44-181-333333 GT of UK VLRGMSC SSN: 7 VLR SCCP Calling Address: Replace SmarTone Macau HLR GTGlobal Title: 852-620-005468 with SPRS GT (corresponding to SmarToneMacau HLR) SSN: 6 HLR MAP level parameters: IMSI: 454-06-09-12345Replace SmarTone Macau IMSI with the corresponding SmarTone HK IMSIMSISDN: 852-624-654321 Keep the SmarTone Macau MSISDN SmarTone HK Sameas above Normal routing based on GT of UK GMSC to UK VLR GMSC/VLR

[0294] Table 18 describes a MAP_PROVIDE_ROAMING_NUMBER response of oneembodiment. This message is sent by the UK VLR to the SmarTone HK GT ofSPRS. The SPRS recognizes it as really intended for the SmarTone MacauHLR and correctly forwards it. TABLE 18 Message sender/ receiver Messagecontent Remarks UK GMSC to SCCP Called Address: SmarTone HK GlobalTitle: 852-620-005468 SmarTone HK GT of SPRS GMSC corresponding toSmarTone Macau SSN: 6 HLR HLR SCCP Calling Address: Global Title:44-181-333333 GT of UK VLR SSN: 7 VLR MAP level parameters: No changeneeded (main parameter is the MSRN) SmarTone HK Same as above Normalrouting based on SmarTone GMSC to SPRS HK GT of SPRS SPRS to SCCP CalledAddress: SmarTone Global Title: 853-624-555555 GT of SmarTone Macau HLRthat Macau GMSC corresponds to the SmarTone HK GT of SPRS SSN: 6 HLRSCCP Calling Address: Global Title: 44-181-333333 GT of UK VLR SSN: 7VLR SmarTone Same as above Normal routing based on GT of Macau GMSC toSmarTone Macau HLR HLR

[0295] Incoming SMS to a UK Subscriber Roaming in Smartone Macau

[0296] The UK SMSC forwards the message to the SmarTone HK GT of theSPRS that correspond to the real SmarTone Macau VMSC. The SPRS relaysthe message to the real SmarTone Macau VMSC.

[0297] Table 19 describes a MAP_Forward_SMS request of one embodiment.This message is sent by the UK SMSC to the SmarTone HK GT of SPRS thatcorresponds to a SmarTone Macau VMSC/SGSN. The SPRS relays it to thereal VMSC/SGSN. TABLE 19 Message sender/ receiver Message contentRemarks UK SCCP Called Address: SMSC/GMSC to Global Title:852-620-005467 SmarTone HK GT of SPRS SmarTone HK corresponding to thereal SmarTone GMSC/SPRS Macau VMSC/SGSN SSN: 8/95 VMSC/SGSN SCCP CallingAddress: Global Title: 44-181-00000003 GT of UK SMSC SSN: 8 SMSC SPRS toSCCP Called Address: SmarTone Global Title: 853-624-555557 GT ofSmarTone Macau Macau GMSC SSN: 8/95 VMSC/SGSN VMSC/SGSN SCCP CallingAddress: Global Title: 44-181-00000003 UK SMSC SSN: 8 SMSC SmarTone HKSame as above Normal routing based on GT of GMSC to VMSC SmarTone MacauVMSC

[0298] Table 20 describes a MAP_Forward_SMS response of one embodiment.This message is sent by the SmarTone MacauVMSC/SGSN to the UK SMSC. Themessage is routed through SPRS to make it looks as if it is coming fromSmarTone HK. TABLE 20 Message sender/ receiver Message content RemarksSmarTone SCCP Called Address: Macau VMSC to Global Title:44-181-00000003 UK SMSC GT SmarTone SSN: 8 SMSC Macau GMSC SCCP CallingAddress: Global Title: 853-624-555557 GT of SmarTone Macau VMSC/SGSNSSN: 8/95 VMSC/SGSN SmarTone HK Same as above Normal routing based on GTof GMSC to SPRS SPRS SPRS to SCCP Called Address: SmarTone HK GlobalTitle: 44-181-00000003 GT of UK SMSC GMSC SSN: 8 SMSC SCCP CallingAddress: Global Title: 852-620-005467 SmarTone HK GT corresponds to thereal SmarTone Macau VMSC/SGSN SSN: 8/95 VMSC/SGSN SmarTone HK Same asabove Normal routing based on GT of UK GMSC to UK SMSC GSMC/SMSC

[0299] MO or Reply SMS for a UK Subscriber Roaming in Smartone Macau

[0300] When a UK subscriber roams in SmarTone Macau to send a SMS/reply,the message will go through the SPRS to the UK SMSC. The SPRS will makethe message look as if it is coming from a SmarTone HK GT.

[0301] Table 21 describes a MAP_Forward_SMS request of one embodiment.This message is sent by the SmarTone MacauVMSC/SGSN to the UK SMSC. Themessage is routed through SPRS to make it looks as if it is coming fromSmarTone HK. TABLE 21 Message sender/ receiver Message content RemarksSmarTone SCCP Called Address: Macau VMSC to Global Title:44-181-00000003 UK SMSC GT SmarTone SSN: 8 SMSC Macau GMSC SCCP CallingAddress: Global Title: 853-624-555557 GT of SmarTone Macau VMSC/SGSNSSN: 8/95 VMSC/SGSN SmarTone Same as above Normal routing based on GT ofMacau GMSC to SPRS SPRS SPRS to SCCP Called Address: SmarTone HK GlobalTitle: 44-181-00000003 GT of UK SMSC GMSC SSN: 8 SMSC SCCP CallingAddress: Global Title: 852-620-005467 SmarTone HK GT corresponds to thereal SmarTone Macau VMSC/SGSN SSN: 8/95 VMSC/SGSN SmarTone HK Same asabove Normal routing based on GT of UK GMSC to UK SMSC GSMC/SMSC

[0302] Table 22 describes a MAP_Forward_SMS response of one embodiment.This message is sent by the UK SMSC to the SmarTone HK GT of the SPRScorresponding to the SmarTone Macau VMSC/SGSN. The SPRS relays theresponse to the real VMSC/SGSN at SmarTone Macau. TABLE 22 Messagesender/ receiver Message content Remarks UK SCCP Called Address:SMSC/GMSC to Global Title: 852-620-005467 SmarTone HK GT of SPRSSmarTone HK corresponding to the real SmarTone GMSC/SPRS Macau VMSC/sGSNSSN: 8 VMSC/SGSN SCCP Calling Address: Global Title: 44-181-00000003 GTof UK SMSC SSN: 8 SMSC SPRS to SCCP Called Address: SmarTone GlobalTitle: 853-624-555557 GT of SmarTone Macau VMSC Macau GMSC SSN: 8 VMSCSCCP Calling Address: Global Title: 44-181-00000003 UK SMSC SSN: 8 SMSCSmarTone Same as above Normal routing based on GT of Macau GMSC toSmarTone Macau VMSC/SGSN VMSC/SGSN

[0303] Incoming SMS to a Smartone Macau Subscriber Roaming in the UK

[0304] When a SmarTone Macau SMSC sends a SMS to a SmarTone Macausubscriber roaming in the UK, it first queries SmarTone Macau HLRthrough MAP SRI-SM. The HLR returns the UK VMSC/SGSN. However, in orderto route the message to UK VMSC/SGSN, the message passes through theSPRS.

[0305] Table 23 describes a MAP_Forward_SMS request of one embodiment.This message is sent by the SmarTone Macau the SMSC, to the UKVMSC/SGSN. The SPRS makes it look like a request coming from theSmarTone HK GT. TABLE 23 Message sender/ receiver Message contentRemarks SmarTone SCCP Called Address: Macau GMSC to Global Title:44-181-00000002 GT of UK VMSC/sGSN SPRS SSN: 8/95 VMSC/SGSN SCCP CallingAddress: Global Title: 853-624-555556 GT of SmarTone Macau SMSC SSN: 8SMSC MAP level parameters: IMSI: 455-00-12345 IMSI of SmarTone Macausubscriber SPRS to SCCP Called Address: SmarTone HK Global Title:44-181-00000002 GT of UK VMSC/SGSN GMSC SSN: 8/95 VMSC/SGSN SCCP CallingAddress: Global Title: 852-620-005469 Replace SmarTone Macau SMSC GTwith SmarTone HK GT (corresponding to SmarTone Macau SMSC) SSN: 8 SMSCMAP level parameters: IMSI: 454-06-09-12345 Replace SmarTone Macau IMSIwith the corresponding SmarTone HK IMSI SmarTone HK Same as above Normalrouting based on GT of UK GMSC to UK VMSC/SGSN VMSC/SGSN

[0306] Table 24 describes a MAP_Forward_SMS response of one embodiment.This message is sent by the UK VMSC/SGSN to the SPRS. The SPRSrecognizes it as really intended for the SmarTone Macau SMSC andcorrectly forwards it. TABLE 24 Message sender/ receiver Message contentRemarks UK GMSC to SCCP Called Address: SmarTone HK Global Title:852-620-005469 SmarTone HK GT of SPRS GMSC corresponding to SmarToneMacau SMSC SSN: 8 SMSC SCCP Calling Address: Global Title:44-181-00000002 GT of UK VMSC/SGSN SSN: 8/95 VMSC/SGSN SmarTone HK Sameas above Normal routing based on GT of GMSC to SPRS SPRS SPRS to SCCPCalled Address: SmarTone Global Title: 853-624-555556 GT of SmarToneMacau SMSC Macau GMSC SSN: 8 SMSC SCCP Calling Address: Global Title:44-181-00000002 GT of UK VMSC/SGSN SSN: 8 VMSC/SGSN SmarTone Same asabove Normal routing based on GT of Macau GMSC to SmarTone Macau SMSCSmarTone Macau SMSC

[0307] MO or Reply SMS for a Smartone Macau Subscriber Roaming in the UK

[0308] When a SmarTone Macau subscriber roams in the UK to send aSMS/reply, the message arrives at the SPRS. The SPRS forwards themessage to the real SmarTone Macau SMSC address. The real SMSC can thenforward the message on in the normal manner.

[0309] Table 25 describes a MAP_Forward_SMS request of one embodiment.This message is sent by the UK VMSC/SGSN to the SmarTone HK GT of theSPRS that corresponds to the SmarTone Macau SMSC. The SPRS sends it tothe real SmarTone Macau SMSC. TABLE 25 Message sender/ receiver Messagecontent Remarks UK GMSC to SCCP Called Address: SmarTone HK GlobalTitle: 852-620-005469 SmarTone HK GT corresponding GMSC to SPRS SmarToneMacau SMSC SSN: 8 VMSC SCCP Calling Address: Global Title:44-181-00000002 GT of UK VMSC SSN: 8/95 VMSC/SGSN MAP level parameters:IMSI: 454-06-09-12345 SmarTone HK IMSI of SmarTone Macau subscriber SPRSto SCCP Called Address: SmarTone Global Title: 853-624-555556 GT ofSmarTone Macau SMSC Macau GMSC SSN: 8 VMSC SCCP Calling Address: GlobalTitle: 44-181-00000002 UK VMSC/SGSN SSN: 8/95 VMSC/SGSN MAP levelparameters: IMSI: 455-00-12345 Replace SmarTone HK IMSI with thecorresponding SmarTone Macau IMSI SmarTone Same as above Normal routingbased on GT of Macau GMSC to SmarTone Macau SMSC SmarTone Macau SMSC

[0310] Table 26 describes a MAP_Forward_SMS response of one embodiment.This message is sent by the SmarTone Macau SMSC to the UK VMSC/SGSN. Themessage goes through the SPRS to make it look as if it is coming fromSmarTone HK. TABLE 26 Message sender/ receiver Message content RemarksSmarTone SCCP Called Address: Macau SMSC to Global Title:44-181-00000002 UK VMSC/SGSN address SmarTone SSN: 8/95 VMSC/SGSN MacauGMSC SCCP Calling Address: Global Title: 853-624-555556 GT of SmarToneMacau SMSC SSN: 8 VMSC SmarTone Same as above Normal routing based on GTof Macau GMSC to SPRS SPRS SPRS to SCCP Called Address: SmarTone HKGlobal Title: 44-181-00000002 GT of UK VMSC/SGSN GMSC SSN: 8/95VMSC/SGSN SCCP Calling Address: Global Title: 852-620-005469 SmarTone HKGT corresponding SmarTone Macau SMSC SSN: 8 VMSC SmarTone HK Same asabove Normal routing based on GT of UK GMSC to UK VMSC VMSC/SGSN

[0311] Receiving SMS for Smartone Macau Subscribers from Overseas andSending SMS by Smartone Macau Subscribers to Overseas

[0312] These functionalities can be supported on the same SPRS node withminimum changes.

[0313] Alternatively, SmarTone Macau can use the SmarTone HK SMSC (aspreviously described) as the relay mechanism for international SMS.

[0314] Sending SMS by Smartone Macau Roaming Partners to Smartone MacauSubscribers to Overseas Non-Partner Networks

[0315] This functionality can be supported on the same SPRS node withminimum changes. In this case, the subscriber uses a SmarTone HK IMSI toregister with a network that has no roaming relationship with ST Macau.The SMS sending operator has a roaming relationship with SmarTone Macau.Based on signal flows as described herein, SRI-SM on ST Macau MSISDNreturns ST Macau IMSI and the non-roaming network MSC. The sendingoperator use thes the ST Macau IMSI to send the SMS to the non-roamingnetwork MSC, which contains only ST HK IMSI, resulting in failure. Onesolution is to change the MSC/VLR address to a SmarTone HK GT duringregistration from non-roaming network with SmarTone HK IMSI. The SGdynamically maintains the mapping which is replicated across twophysical boxes when SG is implemented using two boxes with the same SPC.In this way, an SMS to an outbound roamer in a non-roaming network willcome to the SG first before the SG sends it out to the real MSC (this ispossible since ST HK has the roaming relationship with the network ofthe MSC, even though ST Macau does not).

[0316] Other Scenarios

[0317] This section lists the other messages that are processed by theSPRS.

[0318] Scenarios for Outbound Roamers

[0319] Table 27 describes scenarios for outbound roamers. TABLE 27Message Direction Fields to be changed by SPRSMAP_Send_Routing_Info_For_SM UK -> SCCP Called Address, MSISDN requestSmarTone Macau MAP_Send_Routing_Info_For_SM SmarTone SCCP CallingAddress, Translation Type, response Macau -> UK IMSI, Network NodeNumber (MSC id) MAP_Forward_Short_Message SmarTone SCCP Calling Address,Translation Type request Macau -> UK MAP_Forward_Short_Message UK ->SCCP Called Address response SmarTone Macau MAP_Forward_Short_Message UK-> SCCP Called Address, IMSI request SmarTone MacauMAP_Forward_Short_Message SmarTone SCCP Calling Address, TranslationType response Macau -> UK MAP_Report_SM_Delivery_Status UK -> SCCPCalled Address, MSISDN request SmarTone MacauMAP_Report_SM_Delivery_Status SmarTone SCCP Calling Address, TranslationType response Macau -> UK MAP_Ready_For SM request UK -> SCCP CalledAddress, IMSI SmarTone Macau MAP_Ready_For_SM response SmarTone SCCPCalling Address, Translation Type Macau -> UK MAP_Alert_Service_CentreUK -> SCCP Called Address request SmarTone MacauMAP_Alert_Service_Centre SmarTone SCCP Calling Address, Translation Typeresponse Macau -> UK MAP_Activate_Trace_Mode SmarTone SCCP CallingAddress, Translation Type, request Macau -> UK IMSIMAP_Activate_Trace_Mode UK -> SCCP Called Address response SmarToneMacau MAP_Deactivate_Trace_Mode SmarTone SCCP Calling Address,Translation Type, request Macau -> UK IMSI MAP_Dectivate_Trace_Mode UK-> SCCP Called Address response SmarTone Macau MAP_Purge_MS requestSmarTone SCCP Calling Address, Translation Type, Macau -> UK IMSIMAP_Purge_MS response UK -> SCCP Called Address SmarTone MacauMAP_Send_Authentication_Info UK -> SCCP Called Address, IMSI requestSmarTone Macau MAP_Send_Authentication_Info SmarTone SCCP CallingAddress, Translation Type response Macau -> UKMAP_Delete_Subscriber_Data SmarTone SCCP Calling Address, TranslationType, request Macau -> UK IMSI MAP_Delete_Subscriber_Data UK -> SCCPCalled Address response SmarTone Macau MAP_Register_SS request UK ->SCCP Called Address SmarTone Macau MAP_Register_SS response SmarToneSCCP Calling Address, Translation Type Macau -> UK MAP_Activate_SSrequest UK -> SCCP Called Address SmarTone Macau MAP_Activate_SSresponse SmarTone SCCP Calling Address, Translation Type Macau -> UKMAP_Deactivate_SS request UK -> SCCP Called Address SmarTone MacauMAP_Deactivate_SS response SmarTone SCCP Calling Address, TranslationType Macau -> UK MAP_Interrogate_SS request UK -> SCCP Called AddressSmarTone Macau MAP_Interrogate_SS response SmarTone SCCP Calling AddressMacau -> UK MAP_Purge_MS request UK -> SCCP Called Address, IMSISmarTone Macau MAP_Purge_MS response SmarTone SCCP Calling Address,Translation Type Macau -> UK

[0320] Scenarios for Inbound Roamers

[0321] All the scenarios listed for outbound roamers are valid forinbound roamers as well, and hence need not be listed again. The role ofthe SPRS is different in each case. In She UK->SmarTone Macau directionthe SCCP Called Address must be modified, while in the SmarTone Macau toUK direction the SCCP Calling Address and the Translation Type must bemodified. In either case, any application (MAP) level parameters thatneed modification are modified

[0322] (e.g., IMSI, MSC address, VLR address etc.)

[0323] Smartone Macau Subscriber Roaming in Smartone HK or Operators whohave Roaming Relationships with Smartone Macau

[0324] This is a rather special case. In this case, the SmarTone Macausubscriber should be prevented from using the SmarTone HK IMSI whenroaming in SmarTone HK or any operators who have a roaming relationshipwith SmarTone Macau. The subscriber uses the SmarTone Macau IMSI. Thus,the SmarTone Macau IMSI is used in SmarTone HK or these operators. Inother networks without the roaming relationships, the SmarTone HK IMSIis used.

[0325] One reason for this is that if SmarTone HK IMSI is used, (a)billing will be complex, and (b) SMS could be problematic since thesending SMSC of these operators will use SmarTone Macau IMSI to forwardSMS to the subscribers, which would conflict with the SmarTone HK IMSIin the VMSC/VLR of these operators (unless all map messages between STMCand these operators go through the SPRS node, but that will be lessscalable).

[0326] It is possible that SmarTone Macau has a voice roamingrelationship with operator X but not a GPRS roaming relationship (thereverse typically does not occur). In this case, update locationrejection will depend on whether it is a VLR update location or a SGSNupdate location request. In both cases, the SmarTone HK will direct anyupdate location with the specific IMSI range to the SPRS node. If it isGPRS request, then if there is no GPRS roaming relationship, thenproceed normal, reject otherwise. If it is a VLR request, then if thereis no voice roaming relationship, then proceed normal, reject otherwise.

[0327] SmarTone HK is used as an example. Other operators that haveroaming relationships with SmarTone Macau follow similar procedures.

[0328] Table 28 describes scenarios for a SmarTone Macau SubscriberRoaming in SmarTone HK with a SmarTone HK IMSI. The update_location, orupdate_GPRS_location request is routed to the SPRS by the SmarTone HKGMSC. It is rejected by the SPRS. The SPRS does not forward thismessage; instead, it sends an update_location response with a user error“Unknown Subscriber” or “Roaming Not Allowed”. TABLE 28 Message sender/receiver Message content Remarks SmarTone HK GMSC SCCP Called Address:to SPRS Global Title: 852-620-09- MGT derived from IMSI Update_locationor 12345 Update-gprs_location SSN: 6 HLR request SCCP Calling Address:Global Title: 852-620-333333 GT of SmarTone HK VLR/SGSN SSN: 7/95VLR/SGSN MAP level parameters: IMSI: 454-06-09- SmarTone HK IMSI of12345 SmarTone Macau Subscriber MSC Address: 852-620- GT of SmarTone HKMSC 111111 Or SGSN address: TL-IP-STHK Or IP address of HK SGSN VLR/SGSNNumber: 852-620-333333 GT of SmarTone HK VLR/SGSN SPRS to SmarTone HKSCCP Called Address: GMSC/VLR Global Title: 852-620-333333 GT ofSmarTone HK VLR/SGSN SSN: 7/95 VLR/SGSN Update_location SCCP CallingAddress: Or Global Title: 852-620- SmarTone HK GT of SPRSUpdate_GPRS_location 0005468 response SSN: 6 HLR MAP Level Parameters:User Error Unknown Subscriber or Roaming Not Allowed

[0329] The case of a SmarTone Macau Subscriber Roaming in SmarTone HKwith SmarTone Macau IMSI is treated as normal roaming and is not routedto the SPRS. The update_location request goes directly to SmarToneMacau, and the subsequent Insert_Subscriber_Data goes directly to theSmarTone HK VLR without being routed to the SmarTone HK SPRS.

[0330] Smartone Macau Subscriber Using Smartone HK IMSI Locally

[0331] This is a rather special case. In this case, the SmarTone Macausubscriber is prevented from using the SmarTone HK IMSI when in SmarToneMacau. The subscriber uses the SmarTone Macau IMSI. Thus, the SmarToneMacau IMSI is used in SmarTone HK and Macau; in networks without roamingrelationships, the SmarTone HK IMSI is used.

[0332] Table 29 describes scenarios for a SmarTone Macau Subscriber inSmarTone Macau with a SmarTone HK IMSI. The update location, orupdate_gprs_location request is routed to the SPRS by the SmarTone MacauGMSC. It is rejected by the SPRS. The SPRS does not forward thismessage; instead, it sends an update location response with a user error“Unknown Subscriber” or “Roaming Not Allowed”. TABLE 29 Message sender/receiver Message content Remarks SmarTone SCCP Called Address: MacauGMSC to Global Title: 852-620-09-12345 MGT derived from IMSI SPRS SSN: 6HLR Update_location SCCP Calling Address: or Global Title:853-624-333333 GT of SmarTone Macau Update_gprs VLR/SGSN location SSN:7/95 VLR/SGSN request MAP level parameters: IMSI: 454-06-09-12345SmarTone HK IMSI of SmarTone Macau Subscriber MSC Address: 853-624- GTof SmarTone Macau MSC 111111 Or SGSN address: TL-IP-STMC Or IP addressof STMC SGSN VLR/SGSN Number: 853-624-333333 GT of SmarTone MacauVLR/SGSN SPRS to SCCP Called Address: SmarTone Global Title:853-624-333333 GT of SmarTone Macau Macau VLR/SGSN GMSC/VLR SSN: 7/95VLR/SGSN Update_location SCCP Calling Address: response Global Title:852-620-0005468 SmarTone HK GT of SPRS SSN: 6 HLR MAP Level Parameters:User Error Unknown Subscriber or Roaming Not Allowed

[0333] The case of a SmarTone HK Subscriber Roaming in SmarTone Macauwith a SmarTone HK IMSI is treated as normal roaming and is not routedto the SPRS. The update_location request goes directly to SmarTone HK,and the subsequent Insert_Subscriber_Data goes directly to the SmarToneMacau VLR without being routed to the SPRS.

[0334] Performance and Availability

[0335] The following is an example of conditions in one anticipatedenvironment. Other environments are also anticipated, but not used asspecific examples. This section includes performance and availabilityconsiderations for the SPRS given the example environment.

[0336] The SPRS described herein operates successfully in givenapproximately 12000 inbound/outbound roamers in a given day. Assumedmessage volumes include 20 MAP messages per roamer per day, or about240000 messages per day. Assumes distribution over an 8-hour periodincludes: 30000 messages per hour, or 8-10 messages per second. Peakload is considered to be twice this rate, or about 20 messages persecond.

[0337] The SPRS provides access to services previously unavailable toinbound roamers and outbound roamers. A high-availability platform isrecommended. For example, a platform based on a duplicated architecture.In one embodiment, the SPRS is configured in a pair of systems. It isassigned a single SPC. All E1 links from the same GMSC go to the twosystems functioning as a link set. The SPRS boxes can be connected tothe SmarTone HK GMSCs in a cross-connected mode. Such an arrangement isillustrated in FIG. 13, which shows SmarTone HK GMSCs 1302A. SmarToneMacau includes a GMSC 1302B. SmarTone Macau further includes two SPRSs1306.

[0338] The SPRS boxes can also be connected to the same SmarTone HKGMSC, as shown in FIG. 14. In FIG. 14, SmarTone HK Macau has a GMSC1402B, and two SPRSs 1406 that are connected to a SmarTone HK GMSC1402A.

[0339] Transaction Performance and Volumes

[0340] Unlike the case of voice roaming in which only MAP messages aregoing through the SPRS node (not voice), the GPRS data traffic is alsogoing through the SPRS (directly or indirectly). If it is directlythrough SPRS for GPRS data, SPRS must be equipped with some SGSN/GGSNfunction, in particular the Gp interface. Indirectly, the SPRS can beintegrated with a carrier's existing SGSN or GGSN. However, certainmodifications should be made in order to proxy and relay packets acrossthe SPRS box. Some assumptions made in an example case are as follows:12000 roamers; ½ Mbyte per roamer per day (6000 Mbyte messages per day);distribution over an 8-hour period (750 MB messages per hour 2 Mb persecond). In one embodiment, the SPRS box is equipped with a dualEthernet 100 Mb or gigabit interface. In one embodiment, a Dell 2.4 gHzXeon dual CPU or SunFire 480 dual CPU 900 Mhz with a GB RAM issufficient to achieve this.

[0341] Availability Considerations

[0342] Given the duplicated SS7 architecture previously described, thereare at least two ways to perform load balancing. In one method, eachSPRS box is assigned a different IP address. The DNS server at ST Macauwill has two entries for each of the IP address for any APN notrecognized to have a roaming relationship with ST Macau. Similarly, theDNS server used by the GRX of the roaming partners of ST HK also has twoentries for each of the IP address for any fictitious APN that ST HKassign for SmarTone Macau APNs. DNS update and propagation through GRXcan be controlled or initiated from ST HK by the DNS server at its end,and does not need to involve operations from the roaming partners.

[0343] Another way to achieve load balancing is to assign both SPRSboxes the same virtual IP address in a cluster. Both SPRS boxes aresynchronized on tunnel and PDP context using a shared storage array anda clustered DB. In either case, unlike pure SS7-based SPRS, packets oruser data usage needs to be monitored. A charging gateway interfaceshould be incorporated for billing, including handling prepaidtransactions and fraud prevention.

[0344] Billing

[0345] Billing can be customized for the SPRS for both inbound andoutbound roaming. The following billing arrangement for inbound andoutbound roamers is an example framework. Details depend on commercialagreements between SmarTone HK and SmarTone Macau, and between SmarToneHK and its roaming partners. TAP3 should be used to support SPRS forGPRS roaming

[0346]FIG. 15 illustrates an example billing framework for outboundroamers. A UK billing/clearing house 1502, and a billing system 1504 onthe SmarTone HK/UK side communicate with a billing system 1506 on theSmarTone Macau side. Customer data and invoices 1508 communicate withthe billing system 1506. A special HK-IMSI TAP processor 1512communicates with a database 1520 and the billing system 1506.

[0347] Because a SmarTone Macau outbound roamer will appear to a foreignnetwork operators as a SmarTone HK IMSI, SmarTone HK will be responsiblefor the bill settlement with the foreign operators. TAP files will bepresented to SmarTone HK by the foreign operators who will have no ideawhich SmarTone HK IMSI is special or not. The SmarTone HK side will needto split the TAP files to form files containing special SmarTone HKIMSI. SmarTone HK can relay these files to SmarTone Macau. SmarToneMacau charges the outbound roaming subscriber (MT TAP+IDD)*(1+Y %+X %)for MT calls and (MO TAP)*(1+Y %+X %) for MO calls where Y is the % ofservice charge SmarTone Macau charges to the subscribers and X be the %of charge that SmarTone Macau gives to SmarTone HK. SmarTone Macau paysSmarTone HK TAP charge plus the X % of the subscriber bill. SmarTone HKpays TAP bill to the foreign operators. MACH is a clearing house thatdoes this kind of billing. If SmarTone uses MACH, then billing foroutbound roaming can be arranged with MACH.

[0348]FIG. 16 illustrates an example billing framework for inboundroamers. A UK billing/clearing house 1602, and a billing system 1604 onthe SmarTone HK/UK side communicate with a billing system 1606 on theSmarTone Macau side. Customer data and invoices 1608 communicate withthe billing system 1602. A special HK-IMSI TAP processor 1612communicates with a database 1610 and the billing system 1604.

[0349] Because a SmarTone Macau inbound roamer will appear to foreignnetwork operators as if he is in SmarTone HK whether he is making orreceiving a call, SmarTone HK will be responsible for the billsettlement with the foreign operators.

[0350] SmarTone Macau should split CDR/TAP records whose charging partyis from a non-roaming partner network. These CR/TAP records will bepresented to SmarTone HK by the SmarTone Macau. SmarTone HK will need tomodify the sending operator and any other parameters (such as LAI/LAC,Cell ID, Serving switch) to be a corresponding one defined in itsnetwork. The location-dependent parameters will be assigned a newaddress from SmarTone HK address space that corresponds to the SmarToneMacau location. Different tariffs can be applied for each of thesespecial locations in SmarTone TAP.

[0351] If CDR files are sent from Smartone Macau for these non-roamingpartner networks, then Smartone HK must use a procedure TAP accordingly.

[0352] For MO calls, because Smartone HK can apply a different tariffthat is identical to the MO call originated from Smartone Macau, from acost perspective, the home network of the However, subscribers' billstatements will indicate he/she made a call in HK rather than Macau.Subscriber might not notice due to the close proximity of the twoplaces. But customer care of the home network need be prepared toexplain it.

[0353] For MT calls, the possibility of the home network applyingdifferent IDD top up rates between HK and Macau should be considered. Ifthe two IDD rates are the same, then there is no issue for home networksand the subscribers. If the IDD rate in HK is lowered than in Macau,inbound roamers will be happy, but the home network might not be happy(an unlikely scenario since the home operator should be happy that itmakes some money due to the extended roaming coverage).

[0354] However if the IDD rate in Macau is lowered than HK, inboundroamer will not be too happy, although home operators should be quitehappy. One important fact is that the inbound is getting roaming serviceon a network in Macau, which was not possible in the past.

[0355] Hardware and Software

[0356] Various configurations of components can be used to operate theservices described herein. In one embodiment, the components include aRoamWARE Application Server, SS7 cards, SGSN functions etc.

[0357] Table 30 lists the specifications for different hardwarecomponents for hosting and running the SPRS Service in one embodiment.TABLE 30 S.No Description Qty Comments 1. Sun Fire 480 dual CPU 900 MHz2 Clustered and non-NEBS compliant Or Intel Xeon 2.4 GHz dual CPU 2Clustered but With MS AS/W2k or RedHat not NEBS compliant AS2.1 2. IntelSeptel SS7 Cards 2 Each card has 4 E1 links 3. SS7 protocol stack forSeptel cards 2 MTP2, MTP3, SCCP 4. ASN.1 Compiler 2 5. SQL, RedHat orOracle 9i 2 6 SGSN 2

[0358] The above description of illustrated embodiments of the SPRSmethod and system is not intended to be exhaustive or to limit theinvention to the precise form disclosed. While specific embodiments of,and examples for, the SPRS method and system are described herein forillustrative purposes, various equivalent modifications are possiblewithin the scope of the invention, as those skilled in the relevant artwill recognize. The teachings of the SPRS method and system providedherein can be applied to other communications systems, not only to thecommunications systems described above.

[0359] The elements and acts of the various embodiments described abovecan be combined to provide further embodiments. These and other changescan be made to the SPRS method and system of an embodiment in light ofthe above detailed description.

[0360] In general, in the following claims, the terms used should not beconstrued to limit the SPRS method and system to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all communications systems that operate under theclaims to provide the SPRS method and system. Accordingly, the SPRSmethod and system is not limited by the disclosure, but instead thescope of the SPRS method and system is to be determined entirely by theclaims.

[0361] While certain aspects of the SPRS method and system are presentedbelow in certain claim forms, the inventors contemplate the variousaspects of the SPRS method and system in any number of claim forms. Forexample, while only one aspect of the SPRS method and system is recitedas embodied in an electronically readable medium, other aspects maylikewise be embodied in an electronically readable medium. Accordingly,the inventors reserve the right to add additional claims after filingthe application to pursue such additional claim forms for other aspectsof the SPRS method and system.

What is claimed is:
 1. A method for wireless communication, comprising:receiving a plurality of messages from a home network subscriber device,wherein the device is roaming outside the home network; establishing acommunications link with a destination network, including modifying atleast one of the plurality of messages such that the message appears tothe destination network to originate from a partner network of thedestination network; and transmitting at least one of voice and dataover the communications link.
 2. The method of claim 1, furthercomprising establishing at least one packet data protocol (PDP) tunnelbetween the home network and the destination network.
 3. The method ofclaim 1, wherein the plurality of messages include a GPRS sessionmessage.
 4. The method of claim 1, further comprising routing theplurality of messages to at least one signaling and packet relay system(SPRS) node.
 5. The method of claim 1, wherein the plurality of messagesinclude messages from networks who are not roaming partners of the homenetwork.
 6. The method of claim 1, further comprising the partnernetwork routing messages from the home network to a signaling and packetrelay system (SPRS) node.
 7. The method of claim 1, further comprisingthe home network routing messages from the home network to a signalingand packet relay system (SPRS) node.
 8. The method of claim 1, furthercomprising transmitting modified messages through a GMSC.
 9. The methodof claim 1, wherein the home subscriber device comprises a dual IMSISIM.
 10. The method of claim 1, wherein the home subscriber devicecomprises a modified single IMSI SIM.
 11. The method of claim 1, whereinreceiving the plurality of messages further comprises using a designatedtranslation type.
 12. The method of claim 1, further comprising using aprivate connection to receive the plurality of messages.
 13. The methodof claim 1, wherein receiving the plurality of messages furthercomprises modification of a global title.
 14. The method of claim 1,wherein receiving the plurality of messages further comprises prefixinga called address with a designated routing number.
 15. A mobilecommunications system for transmitting voice and data, the systemcomprising: a sponsored network; a sponsoring network; a plurality ofpartner networks, wherein the plurality of partner networks have roamingagreements with the sponsoring network, and have no roaming agreementswith the sponsored network; and at least one signaling packet relaysystem (SPRS) node coupled to the sponsored network and the sponsoringnetwork, wherein messages between the partner networks and the sponsorednetwork are routed to the SPRS node and modified to appear as if themessages are between the sponsoring network and the partner networks.16. The mobile communications system of claim 15, wherein the at leastone SPRS node comprises an SPRS node at the sponsoring network, whereinthe SPRS node is coupled to the sponsored network through a first packetdata relay (PDP) tunnel, and coupled to the partner networks through asecond PDP tunnel.
 17. The mobile communications system of claim 15,wherein SPRS node is further coupled to the sponsored network and to thepartner network through at least one SS7 node.
 18. The mobilecommunications system of claim 15, wherein the first packet data relay(PDP) tunnel, and the second PDP tunnel each comprise a general packetradio service (GPRS) roaming exchange (GRX).
 19. The mobilecommunications system of claim 18, wherein one of the GRXs is coupled toan SGSN at the partner network, and another one of the GRXs is coupledto a GGSN at the sponsored network.
 20. The mobile communications systemof claim 15, wherein routing includes using a designated translationtype, the system further comprising: an SPRS coupled to a GMSC of thesponsoring network; at least one signal transfer point (STP) coupled tothe sponsoring network GMSC; and a GMSC of the sponsored network coupledto the at least one STP.
 21. The mobile communications system of claim15, wherein routing includes using a private connection, the systemfurther comprising: an SPRS coupled to a GMSC of the sponsoring networkand further coupled to a GMSC of the sponsored network coupled; and atleast one signal transfer point (STP) coupled between the sponsoringnetwork GMSC and the sponsored network GMSC.
 22. The mobilecommunications system of claim 15, wherein routing includes modifying aglobal title, the system further comprising: an SPRS coupled to a GMSCof the sponsored network; and at least one signal transfer point coupledbetween a sponsoring network GMSC and the sponsored network GMSC. 23.The mobile communications system of claim 15, wherein the at least oneSPRS comprises: a first SPRS coupled to a GMSC of the sponsored network;and a second SPRS coupled to a GMSC of the sponsoring network.
 24. Acomputer readable medium having stored thereon instructions executed ina mobile communications system for: receiving a plurality of messagesfrom a home network subscriber device, wherein the device is roamingoutside the home network; establishing a communications link with adestination network, including modifying at least one of the pluralityof messages such that the message appears to a destination network tooriginate from a partner network of the destination network; andtransmitting at least one of voice and data over the communicationslink.
 25. The computer readable medium of claim 24, wherein theinstructions are further executed in the mobile communications systemfor establishing at least one packet data protocol (PDP) tunnel betweenthe home network and the destination network.
 26. The computer readablemedium of claim 24, wherein the plurality of messages include a GPRSsession message.
 27. The computer readable medium of claim 24, whereinthe instructions are further executed in the mobile communicationssystem for routing the plurality of messages to at least one signalingand packet relay system (SPRS) node.
 28. The computer readable medium ofclaim 24, wherein the plurality of messages include messages fromnetworks who are not roaming partners of the home network.
 29. Thecomputer readable medium of claim 24, wherein the instructions arefurther executed in the mobile communications system for causing thepartner network routing messages from the home network to a signalingand packet relay system (SPRS) node.
 30. The computer readable medium ofclaim 24, wherein the instructions are further executed in the mobilecommunications system for causing the home network routing messages fromthe home network to a signaling and packet relay system (SPRS) node. 31.The computer readable medium of claim 24, wherein the instructions arefurther executed in the mobile communications system for transmittingmodified messages through a GMSC.
 32. The computer readable medium ofclaim 24, wherein the home subscriber device comprises a dual IMSI SIM.33. The computer readable medium of claim 24, wherein the homesubscriber device comprises a modified single IMSI SIM.
 34. The computerreadable medium of claim 24, wherein receiving the plurality of messagesfurther comprises using a designated translation type.
 35. The computerreadable medium of claim 24, wherein the instructions are furtherexecuted in the mobile communications system for using a privateconnection to receive the plurality of messages.
 36. The computerreadable medium of claim 24, wherein receiving the plurality of messagesfurther comprises modification of a global title.
 37. The computerreadable medium of claim 24, wherein receiving the plurality of messagesfurther comprises prefixing a called address with a designated routingnumber.